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Non-heat-treated Al–Mg-based die casting alloys have been developed for the structural parts of automobiles. In previous studies, alloy compositions with at least 1.0%Si have been proposed to reduce the hot tearing susceptibility (HTS). On the other hand, the increase in the Si content reduces the ductility. For some automotive body structures, Al–Mg alloy die castings with Si content exceeding 1.0% should not have the required ductility. This study aims to develop an Al–Mg alloy with both high ductility and low HTS by investigating the following three characteristics of an Al–4.5Mg–1.0Mn alloy with 0.2%Si added: (1) additional elements to reduce the HTS, (2) the associated mechanical properties (requirements for the automotive company: 0.2% proof stress ≥ 140 MPa and fracture elongation ≥ 15%), and (3) the mechanism of decreasing the HTS. It was revealed that the co-addition of 0.025%Sr, 0.08%Ti, and 0.016%B reduced the HTS when the hydrogen content of the melt was 0.5–1.0 mL/100 g Al. Furthermore, the 0.2% proof stress and fracture elongation of a lower link arm produced via HPDC with the above composition were found to achieve the requirements. It was also indicated that the mechanism of decrease in the HTS by the Sr addition should result from the decrease in the thermal tensile load due to the formation of hydrogen porosity at a lower solid fraction than that without Sr. It is suggested that when 0.025%Sr, 0.08%Ti, and 0.016%B are added to the Al–4.5Mg–1.0Mn–0.2Si alloy, non-heat-treated automotive structural parts with both high ductility and low HTS will be obtained by high-pressure die casting. [ABSTRACT FROM AUTHOR]

Rubber tires, as an important part of automobiles, are produced by molding operation under molten temperature and high pressure. However, mold fouling during the vulcanization process is a rock-ribbed problem that not only leads to the loss in productivity and degradation of product quality but also results in severe accidents and enormous economic losses. In this work, a promising Co-Mo/CeO2 composite coating was electroplated and investigated to solve the mold fouling problem. The effect of CeO2 content on the surface morphology, microstructure, hardness, tribological and electrochemical behavior is systematically studied. With an addition of 10 g/L CeO2, the Co-Mo/CeO2 composite coating not only possesses the highest microhardness, the best wear and corrosion resistance but also features hydrophobicity and remarkable mold antifouling performance. This study offers a new strategy for producing composite coatings with excellent performance to reduce mold fouling in practical tire industry applications. Co-Mo/CeO2 composite coatings with excellent corrosion and wear resistance as well as low surface energy were simply electrodeposited and applicated for antifouling in tire mold for the first time. [ABSTRACT FROM AUTHOR]

Various petroleum-based polymers are being widely used in the automobile and aviation industries. However, the scarcity of petroleum-based polymers, their lack of biodegradability, and stringent environmental regulations lead researchers to look for green biopolymers/biocomposites as an alternative to petroleum-based polymers. Biopolymers have potential applications in various exterior and interior parts of an automobile, including steering, doors, wheels, electrical components, engine parts, exhaust systems, and so on. Almost all automakers are currently focusing on developing novel biopolymers, and they have successfully used bio-based materials in their newer version of automobiles, eventually replacing petroleum-based polymers. However, biopolymer uses in the aviation industry are not yet widespread because of stricter property requirements. Some advanced biopolymers are applied in interior aircraft panels, waste and drainage systems, engine components, cockpits, portholes, windshields, aircraft tires and inner tubes, exterior lighting, and helicopter windscreens. These materials are expected to substitute traditional plastics with the help of modifying agents, cutting-edge manufacturing technology, and a reliable supply chain of biopolymers. This review discusses the current practices, recent advances, and prospects of biopolymers in automotive and aviation engineering applications. [ABSTRACT FROM AUTHOR]

Electrochemical Machining (ECM) is an important advanced machining process useful to obtain good quality finish with a stress-free and crack free machined surface. Machining performance of the process is independent of the hardness of the material. Objective of this study is to assess the effect of process parameters of the ECM on material removal rate (MRR) and surface roughness (SR) during machining of EN-31 alloy steel. The EN-31 alloy steel is widely used in the manufacturing industry for making plastic molding dies, gears, automobile parts, etc. The machining experiments have been conducted according to the design of experiments based on Central Composite Face Centered Design (CCFCD) with three independent input parameters – voltage, electrolyte concentration and electrolyte flow rate, and two response parameters – material removal rate (MRR) and surface roughness (SR). Response Surface Methodology (RSM) has been used to develop the empirical relationship between the response parameters and the input process parameters. Optimization has been carried out to maximize the MRR and minimize the SR using desirability function. [ABSTRACT FROM AUTHOR]

Advanced high-strength steel is widely used in automobile production and manufacturing, for its advantages of light weight, high strength, and good formability. Compared with common steel plate, higher forming forces are required during the stamping forming process of advanced high-strength steel plate due to its continuous strength improvement. The higher forming forces directly result in a sharp increase in the reactive force on the stamping die, which easily cause inevitable fatigue deformation and damage fracture. In view of the above problems, the stamping forming process of an advanced high-strength steel anti-collision beam part and the loading bearing condition of the stamping die were explored. On basis of the theory of topology optimization, the structure of the stamping die was optimized to obtain the qualified stamping parts and the lesser quality punch. A method based on the node contact force conversion was proposed, and the reactive force on the stamping die during the forming process was obtained to function as the load boundary condition of topology optimization. Geometric reconstruction of the stamping die was implemented referring to the topology optimization results. The final result reveals that the lightweight punch and the qualified stamping part without fatigue deformation can be efficiently achieved through topology optimization. [ABSTRACT FROM AUTHOR]

Cold forging dies are manufactured through the shrink fit process to withstand high pressure loads, but fatigue failure eventually occurs due to repeated compressive stresses. The life cycle until fatigue failure was defined as the limit life, and attempts were made to predict the die life based on finite element method. However, accurate prediction was impossible owing to uncontrollable environmental variables. Consequently, it is impossible to clearly determine the die replacement cycle, resulting in negative consequences such as poor quality, production delay, and cost increase. Various environmental factors affecting the prediction of die life cycle result in the increase or decrease of the forming load, which is an important variable that determines the die life cycle. In this study, a system for monitoring load data generated from forging facilities was developed based on a piezo sensor. In addition, the die life cycle was more accurately predicted by using the forming load data measured in real time, and a die life management system that can determine the die replacement cycle was applied to the automobile steering parts production line. [ABSTRACT FROM AUTHOR]

During the development of an automobile part obtained by stamping process, time and money are required aiming process planning and setup of a new tooling. One of the difficulties in stamping is to know if the chosen material will have sufficient formability to reach the final form required by the project. Because of this difficulty, it is very interesting to propose a method that can accurately simulate the forming process. The failure criteria can be mathematical or empirical models capable of determining the onset of necking for each stress/strain states. It is interesting to find a failure criterion that can be easily determined and provides a good ability to detect the failure accurately. In this study, six different failure criteria were studied. Five of them are classified as ductile damage models and they depend on the stress triaxiality and plastic strain. The last criterion depends only on the deformations in the main directions and it is called the forming limit curve (FLC). Computational models through finite element analysis (FEA) were used. The formability was evaluated by monitoring the displacement of the punch until the failure of the material. Lou and Huh criterion and Johson-Cook criterion have been able to provide approximation errors in the range of 0.7–5% which makes them interesting for practical implementation in the industry. [ABSTRACT FROM AUTHOR]

7000 series high strength aluminum alloys are increasingly used in manufacturing automobile body parts to meet the more stringent demands for automobile lightweight. Hot stamping of 7000 series high strength aluminum alloys is a complex thermal-mechanical coupling process and precise simulation is needed to predict material fracture. To obtain damage model of 7075 aluminum alloy in hot stamping, five different stress triaxiality specimens were designed. The fracture strain, critical strain and average stress triaxiality of different specimens were obtained by the hybrid finite element simulation and experiment (FE-EXP) method. GISSMO model of 7075 aluminum alloy at 400 °C was established. Compared with the experimental results of U-shaped part hot stamping under different lubrication conditions, the calibrated GISSMO model was demonstrated to predict the damage behavior of 7075 aluminum alloy during high temperature deformation accurately. [ABSTRACT FROM AUTHOR]

Reducing the disturbance of parameter fluctuations to the system is very important to the robustness of stamping product quality. In this paper, a 6-sigma robust optimization design method based on residual error and radial basis interpolation is proposed to weaken the negative influence of parameter fluctuations. Not only the key controllable parameters but also the key noise parameters are considered by grey relational analysis (GRA) to screen the parameters that have an important influence on the stamping quality. In order to reflect the relationship between key parameters and forming quality more precisely, the polynomial response surface model is improved based on residual error and radial basis function (RBF), and solved by the multi-population co-evolutionary immune algorithm (MPCEIA). Moreover, the solution of deterministic optimization is designed with 6-sigma robust optimization to improve the robustness of the system to the parameter fluctuations. Finally, the method is applied to the design of a complex automobile cover part, proving its effectiveness and reliability. [ABSTRACT FROM AUTHOR]

Machined parts of aluminum alloys are used in a wide range of engineering applications, such as automobile parts. Many types of tool wear may occur during machining of these alloys, which reduces tool life. Therefore, it is beneficial to undertake comprehensive studies to improve tool life (reduce tool wear) in machining aluminum alloys. In the present study, the micro-textured cutting tool's performance is compared to the non-textured tool with chip breaker (and without chip breaker) when used cutting fluid under different cooling-lubrication methods. A literature review denoted that no experimental work is available for a comparison study between texture and chip breaker performance. Scanning electron microscope (SEM) images and energy-dispersive X-ray spectroscopy (EDX) were utilized to analyze the workpiece's surface. Although many scholars have stated that the chip breaker has a good effect on cutting performance, this research showed that the chip breaker has no positive effect on reducing tool wear in aluminum machining. Nonetheless, the SEM images denote a maximum of 30% and 36% improvement in surface quality and tool life, respectively, a considerable decrease in adhesion, abrasion, and breakage wear, and a drastic reduction in the density of defective regions in the workpiece surface when the optimum micro-textured tool was used. [ABSTRACT FROM AUTHOR]

In the study, the pre-strain effect on hydrogen embrittlement property of the ultra-high-strength transformation-induced plasticity (TRIP)-aided bainitic ferrite (TBF) steel was investigated towards application for automobile frame parts. Specifically, 3–10% tensile pre-strain suppressed hydrogen-induced mechanical degradation relative to total elongation (pre-strain + elongation after hydrogen charging) while 12–15% pre-strained specimen did not exhibit elongation after hydrogen charging. The advantageous effect of the 3–10% pre-strain was attributed to the suppression of crack initiation related to retained austenite. Specifically, the TRIP by pre-straining decreased the volume fraction of retained austenite before hydrogen charging, thereby reducing existing probabilities of preferential crack initiation sites and propagation paths. Conversely, high pre-strain such as 12–15% does not effectively work due to work hardening resulting in increases in hydrogen embrittlement susceptibility and a significant increase in hydrogen content due to the multiplication of dislocations. [ABSTRACT FROM AUTHOR]

In recent years, the automotive industry has faced an unprecedented crisis. In particular, the zero-inventory approach, which has been widely pursued by many automobile companies, seems to be impractical in some real production contexts since it requires an inventory of all parts but in low amounts. In this paper, we investigate a new logistics method which collects automobile parts by integrating the progress-lane (P-LANE) into the corresponding vehicle routing problem. We propose a mixed integer programming formulation for this new model, which can simultaneously determines the trip routes to collect automobile parts, as well as the P-LANE that each collected part should be assigned to, so as to minimize the total costs of the production and inbound logistics. The comparison with the zero-inventory model shows that the use of the P-LANE within the milk-run system could significantly decrease the total costs and also improve the transportation efficiency. To be specific, for small and large size instances, the total costs of the zero-inventory model are about 10% and 30% higher than the ones with P-LANE, respectively, which suggests that the periodic part collection model with P-LANE could be more appropriate for automobile manufacturing. [ABSTRACT FROM AUTHOR]

Rubber seals are used in the assemblies of mechanical parts in automobiles and aircrafts to prevent lubricant leakage and inclusion of foreign object. Because of the recent increase in the warranty periods of mechanical parts for automobiles, there is a need for longer service lives than those of existing products, and there is an even greater need for performance-related reliability during usage. This study analyzes the deformation behavior of rubber seals, including an overmold, used in the assemblies of mechanical parts. To improve the reliability of the analysis for rubber seal, three types of static experiments on rubber were conducted to obtain rubber properties. The experimental results were used to perform a hyper-elastic analysis considering rubber seal contact. The deformation analysis for rubber seal was performed to predict the performance after the assembling process. Moreover, a Monte Carlo simulation considering the probabilistic distribution of the mechanical properties of the rubber was performed to identify the effect of uncertainties in the rubber properties on deformation behavior of rubber seal. The pre- and post-deformation distributions of the rubber seal assembly were derived from the results of the Monte Carlo simulation, and they were used to evaluate the stability of the mechanical parts during the assembling process. [ABSTRACT FROM AUTHOR]

The growing demand for prolonged fatigue life of automotive parts and components requires elaboration of their motion in Cartesian space having six degrees of freedom (DOF). Recently, the canonical Steward platform, consisting of six displacement sensors mounted on two parallel platforms, was introduced to comply with this request. In order to apply this pose sensor to automotive applications, the following two important matters are investigated in this study. First, update Jacobian is proposed as a faster and more stable numerical method to solve the forward kinematic problem without any iteration process. Second, the attachment position and initial configuration of the Stewart platform must be adjustable to avoid the interference with other components due to space constraints under the hood of automotive vehicle. In this case, however, the Jacobian matrix which converts six displacement components into a six DOF pose vector is prone to be ill-conditioned so that the converting accuracy becomes worse. The L1-norm of each row in the Jacobian matrix quantifies how much the error would be provoked according to the given kinematic geometry. Hence, it can be used here as a reliable error indicator. Furthermore, several numerical examples are discussed to demonstrate what to consider when designing a six DOF pose sensor for automotive applications. [ABSTRACT FROM AUTHOR]

Automotive body frame comprises semi-rigid connected thin-walled beams (TWBs) that are fabricated from several stamped metal sheets. At conceptual design stage, cross-sectional shape design of the frame is a critical and intractable technique. In practice, design engineers mostly rely on empirical and intuitive trial-and-error approach to make decisions on the design of cross-sectional shape. This approach is laborious, time-consuming and unreliable, thus this article proposes a two-level multiple cross-sectional shape optimization approach. Our previously proposed transfer stiffness matrix method (TSMM) is adopted for the exact static and dynamic analyses of the frame. The dynamic stiffness matrix is refined by Love’s rod theory to take into account Poisson’s ratio effect. Moreover, scale vector method is introduced to remarkably reduce design variables. Then the shape optimization problem is formulated as a mass minimization problem, with exact static stiffness, dynamic frequency stiffness and four manufacturing constraints. Genetic algorithm (GA) is employed to solve the constrained nonlinear optimization problem. Afterwards, numerical examples with both of top-level and low-level shape optimization are carried out to demonstrate the validity of the proposed method. At last, parallel computing is introduced to notably speed up the optimization, and the shape optimization method is integrated into our object-oriented MATLAB toolbox to promote the conceptual development of auto-body. [ABSTRACT FROM AUTHOR]

In this study, the design optimization process of a vehicle front body structure made of short-fiber composites is proposed. The aim of the optimization process is to reduce the weight in consideration of quality and production characteristics. Injection molding of short-fiber-reinforced composites leads to anisotropic material properties which depend on the dimensions of the structure, a finding which is taken into account in this research. First, a basic design is derived through topology optimization that assumes linear isotropic material properties. Second, anisotropic properties are derived by an injection molding analysis for each design point and are applied to a structural analysis to consider the anisotropic properties according to the dimensions of the structure. Third, based on the analysis results, a surrogate model is created and multi-objective optimization is conducted. The Pareto region, inversely correlated with the lightweight effect, the quality and the production characteristics, is identified. The optimal solution based on the design goal is derived using the goal-programing method. [ABSTRACT FROM AUTHOR]

Purpose: We are interested in what policy insights can be transferred from EU countries that have been most successful in introducing EVs to those that are debating policy options. As we use a model to explore this, we are also interested in the application of modelling, seeking to understand if real world policies and results can be replicated in a model and, more generally, the challenges to the use of modelling in policy appraisal. Methods: We use the EC-JRC Powertrain Technology Transition Market Agent Model (PTTMAM), a system dynamics model based around the interactions of conceptual market agent groups in the EU. We perform iterative scenario tests to replicate the policies carried out in the Netherlands and the UK in recent years in an attempt to achieve similar results in EV sales. We then transfer the policy scenarios to other EU member states and assess the transferability of the policies. Results: Reasonable approximations of the Netherlands and UK EV policies and sales were achieved and implemented in other EU member states. Conclusion: We find that the PTTMAM is fit-for-purpose and can replicate successful policies to a certain degree. Policy success is sensitive to country specific conditions, and a system dynamics model like the PTTMAM can help identify which conditions react to which policy stimulus. There are challenges to modelling in policy appraisal, such as the subjectivity of the modeller and flexibility to specific conditions, which must be kept transparent for the model to be a relevant tool for policy making. [ABSTRACT FROM AUTHOR]

Stretch-flangeability evaluated using hole-expansion testing represents the ability of sheet materials to resist edge fracture during complex shape forming. Despite a property imperative for automotive part applications of advanced high-strength steels, factors governing stretch-flangeability are not yet well understood. In this study, the mechanical properties of a selected group of materials with different microstructures were investigated using tensile, fracture toughness, and hole-expansion tests to find the factor governing the stretch-flangeability that is universally applicable to a variety of metallic materials. It was found that the fracture toughness of materials, measured using the fracture initiation energy, is a universal factor governing stretch-flangeability. We verified that fracture toughness is the key factor governing stretch-flangeability, showing that the hole-expansion ratio could be well predicted using finite element analysis associated with a simple ductile damage model, without explicitly taking into account the microstructural complexity of each specimen. This validates the use of the fracture toughness as a key factor of stretch-flangeability. [ABSTRACT FROM AUTHOR]

Ultrahigh-strength steel (UHSS), such as DP980, has been widely used in automotive structural components to further reduce the weight of the autobody and improve the crashworthiness performance. However, UHSS sheets demonstrate more obvious kinematic hardening, which results in severe springback. In the present work, the kinematic hardening of typical Quenching and Partitioning steel, QP980, which is the typical steel of third generation of UHSS, is tracked by using a nonsaturating kinematic (NSK) Swift model in order to simulate the loading process more accurately. For unloading process, inertia relief is adopted as a new control approach in springback calculation. The experiment results show that the NSK Swift model improves the springback prediction accuracy greatly compared with that predicted by isotropic hardening model, and the inertia relief is validated as an accurate and efficient springback calculation method. Moreover, springback compensation based on the NSK Swift model can reach acceptable tolerance as ±0.5 mm through the iterative compensation method in LS-Dyna. [ABSTRACT FROM AUTHOR]

On the basis of metallographic monitoring of semimanufactured steel pieces and automobile parts, it is shown that prediction of the properties of articles on the basis of the criterion of microhardness of individual structural constituents and the difference in the values of the criterion represents an effective approach. [ABSTRACT FROM AUTHOR]

A new method to compensate for the springback of a formed part was introduced in this study. The development of stamping tools for the rear reinforcement plate of a door panel was used for the experiment. A three-dimensional (3D) scanner was utilized to scan the formed part. Compared with the design model, the deviation and springback angle of the formed part were obtained. Furthermore, the inspection results measured by a traditional special fixture were compared with the results of the 3D scanner. Finally, the 3D scanning data were used to compensate tool surfaces, and the tools were remanufactured on the basis of the compensated tool surfaces. The final stamping parts were measured by a special fixture after die tryout. The inspection results demonstrated that 15 of 18 measuring points can satisfy the geometrical tolerances, thus indicating that the qualified rate of this product can reach 83.33 % the first time the springback is compensated by using 3D scanning method. The results prove that 3D scanning data is more accurate and complete than the traditional method, and the springback compensation by this method can effectively reduce die tryout time. [ABSTRACT FROM AUTHOR]

With the increasing use of advanced high strength steel for automotive components, hydro-formed hollow components have the advantage of both high strength and high stiffness. In order to manufacture a 780 MPa torsion beam satisfied with both improved safety and lightweight, hydro-forming process of 780 MPa torsion beam was studied by experimental research and numerical simulation. Pre-form design according to central composite method was carried out to avoid forming flash and bursting during hydro-forming. Response surface model of the effect of pre-form structure on thickness distribution was developed, and significance of structural parameters on the response value was discussed. According to the genetic algorithm, an optimum pre-form shape has been obtained. An experiment was carried out on the basis of the optimum pre-form shape, and the effect of loading paths was deeply discussed on hydro-forming process. It is shown that the axial feeding within acceptable range can significantly improve the thickness distribution and forming accuracy. Finally, a well hydro-formed torsion beam is manufactured. [ABSTRACT FROM AUTHOR]

This paper deals with the design procedure of the tool and process for automotive bracket part fabrication. Finite element analysis is introduced to the progressive process to investigate the causes of defects that occur during the forming and bending stages. This paper proposes a new guideline for the progressive process design that modifies the intermediate stages in the progressive process. Finite element analysis and pilot tests are performed again using new strip layout and tool shapes to confirm the validity of the proposed process design. The analysis result shows that the modified process design eliminates defects such as non-uniform thickness distribution and initiation of crack. Then, the automotive bracket part is successfully fabricated through pilot tests using the progressive tools designed in accordance with the proposed guideline. [ABSTRACT FROM AUTHOR]

Stamping direction (SD) of an automotive part is investigated by using multi-objective optimization concerning forming process of sheet metal and validated by utilizing finite element (FE) method. To improve uniformity of feeding resistance and contact conditions (e.g., number and location of contact point) between tools and an automotive part, five mathematical models for optimization have been studied, and evaluation function of multi-objective optimization has been formulated by the sum-weighted method. The mathematical models presented are solved effectively by using the adaptive genetic algorithm (GA), and tipping angles of the automotive part are different from those determined by AutoForm system. Solutions of SD are global optima. The computational programs are highly efficient and stable. The optimal SD obtained has been validated by FE method. Comparing the adaptive GA with the other three methods determined in AutoForm, we find that the stamped part using the adaptive GA has a good forming quality and with the biggest deforming ample degree value (11.3 %). For the feasible regions of blank-holder force and friction coefficient, the results indicate that the adaptive GA characterizes a biggest limit in the four tipping angles, which has been supported experimentally. Methods of SD presented are helpful for quickly getting a compromise among process parameters of an automotive part. [ABSTRACT FROM AUTHOR]

During the operation of the brakes the behavior of the brake fluid in the brake piping is one element that has a large effect on feel and on transient pressure characteristics. In the present study investigates the effect of fitting a brake pipe with different inner diameters to each wheel at the rear axle on the brake performance and vehicle dynamics. Theoretical analysis and road tests were conducted and applied on a Fiat 128 vehicle to investigate the changes in brake efficiency and brake force balance. The theoretical and experimental results showed the improvement of the car brake efficiency and brake balance when fitting a brake pipe with the same inner diameter (without orifice) for each wheel. [ABSTRACT FROM AUTHOR]

This study proposed a method of developing an intelligent recommendation system for automotive parts assembly. The proposed system will display the detailed information and the list components which make up the relevant part that an user wants through the database using the ontology when selecting an automotive part that an user intends to learn or to be guided of. This study is to design task ontology based on Hierarchical Taxonomy so as to achieve productivity enhancement, cost reduction and outcome improvement through recommendations based on intelligence and personalization depending on the worker's present situation or context of task in charge when assembly of automotive parts is conducted. For this, composing elements of an engine and upper/lower relationships were expressed using hierarchical structure Taxonomy. The intelligent recommendation system for parts is offered to users through determining the automatic recommendation order between parts using the weights. This study has experimented the principles of the recommendation system and the method of setting the weights by setting two scenarios. [ABSTRACT FROM AUTHOR]

Accurately predicting the fatigue life is the basis for the reliability and lightweight design of automobile parts. However, the predicted lives under service loadings on the basis of the S-N curve from constant amplitude loads from existing methods often seems conservative compared with real lives, because of ignoring the strengthening effect of loads below fatigue limit. In this paper, a fatigue damage model, which is modification of Miner's Rule, was established for the fatigue assessment under service loadings by means of taking into account the strengthening and damaging effects of loads below fatigue limit. Then this model and conventional Miner's Rule are applied to the estimate the fatigue life of a torsion beam rear axle using the loading history recorded on proving ground. Finally, verification tests are performed on MTS road load simulator test bed. Results of predicted lives and fatigue tests demonstrate that the accuracy of the predicted life could be greatly improved by taking into account the strengthening and damaging effect of loads below fatigue limit. [ABSTRACT FROM AUTHOR]

The effect of the as-received condition of an aluminum alloy on its stampability in the production of an automobile part is examined. An explanation is given of the process of using software package PAM-STAMP to model the sheet-stamping operation. The results obtained from the modeling clearly show the need to correctly choose not only the material that will be used to make the part but also the properties that it will have as a result of the condition in which it is received. [ABSTRACT FROM AUTHOR]

Springback is the most common defect in sheet metal forming, especially for the advanced high-strength steel (AHSS) parts. The compensation method is an effective way to overcome this defect by modifying the die-face. A new geometrical springback compensation algorithm based on the advanced displacement adjustment (DA) method is proposed in this paper for automobile AHSS parts. The die-face is reconstructed by the non-uniform rational B-spline surface with the advantage of UV curves; furthermore, the continuity and topology of the die-face are also studied. The high-quality geometry compensation die-face obtained from this algorithm can be directly applied to actual machining. To reduce the time and cost of the die manufacturing, this algorithm is seamlessly integrated into the CATIA platform. A new compensation user-defined feature is created, which can meet the need for iterative compensation and parametric association. At the end of this paper, two engineering examples of AHSS parts verify the feasibility and validity of this algorithm and system. [ABSTRACT FROM AUTHOR]

Preventive evaluation of costs is strategic for the whole manufacturing industry and especially for companies whose manufacturing technology is based on expensive machinery, tools and fixtures, such as injection moulding of aluminium. Preventive evaluation of production costs and time is even more relevant for the mould producer, in order to quickly prepare commercial offers with an acceptable degree of accuracy. In this paper, the application of a parametric approach for the evaluation of the labour content in the production of mould for injection moulding of aluminium automotive components is presented. The approach is based on simple geometrical features of the part to be produced derived from their 3D model using the basic tools of CAD systems. The data acquired from a specialized mould production company was analysed by factor analysis in order to determine the structure of the labour content and then parametric modelling was applied. The results evidenced an acceptable degree of accuracy of the estimate combined with an exceptional ease of application. [ABSTRACT FROM AUTHOR]

Second generation advanced high strength steel is one promising material of choice for modern automotive structural parts because of its outstanding maximal elongation and tensile strength. Nonetheless there is still a lack of corrosion protection for this material due to the fact that cost efficient hot dip galvanizing cannot be applied. The reason for the insufficient coatability with zinc is found in the segregation of manganese to the surface during annealing and the formation of manganese oxides prior coating. This work analyses the structure and chemical composition of the surface oxides on so called nano-TWIP (twinning induced plasticity) steel on the nanoscopic scale after hot dip galvanizing in a simulator with employed analytical methods comprising scanning Auger electron spectroscopy (SAES), energy dispersive X-ray spectroscopy (EDX), and focused ion beam (FIB) for cross section preparation. By the combination of these methods, it was possible to obtain detailed chemical images serving a better understanding which processes exactly occur on the surface of this novel kind of steel and how to promote in the future for this material system galvanic protection. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Targeting to improve dimensional accuracy of automotive body panels, elastic deformation of stamping die structure and blank thinning are considered for compensation on the die surfaces. The thinning distribution on the deformed blank is extracted from stamping process simulation results and converted into first quantitative compensation. The boundary load required for die structural FEM analysis can be automatically mapped from process simulation results by using an updated load mapping algorithm, and the die deflection is then calculated and the deflection of die surfaces is transferred into second quantitative compensation. These two quantitative contributions are referred together for the compensation on the die surface model. The proposed methodologies have been programmed and can be integrated with LS-Dyna and HyperWorks or with Autoform and CATIA. Additionally, a software toolkit used to calculate the contacting ratio between the formed blank and die face has also been developed to automatically evaluate the effectiveness of die face compensation rather than virtually check the contacting ratio. The proposed methodologies and developed software have been verified by a case study of process and die design for an automotive panel part, showing the benefit in improving the contacting ratio. [ABSTRACT FROM AUTHOR]

The manufacturability evaluation is an important component of virtual manufacturing and concurrent engineering, and hot spot of this research is focused on manufacturability evaluation based on feature at present. In this paper, using the object-oriented modeling methodology, according to the manufacturing features of the gears used in automobile, the gears are classified into cylindrical gears and bevel gears to carry on the feature modeling separately; the manufacturing resources are classified into the basic information of the manufacturing equipments and the feature processing capability information to establish information models, and the association relationship of features, machine tools, and process equipment is established simultaneously. All of the models established in the article provide the information support for manufacturability evaluation and lay a good foundation for virtual manufacturing. [ABSTRACT FROM AUTHOR]

As automobile body panels are one kind of sheet metal part with groups of free form surfaces, the process planning is more complicated than common sheet metal stamping to implode effectively and practically. Based on KBE, new frameworks have been presented as intelligent master model at the system level and as procedure model at the activity level. In accordance with these frameworks, an intelligent CAPP system has been specifically developed. Based on feature technology, features have been extracted and represented by the object-oriented method. Stamping features and their parameters have been defined and extracted based on feature technology and stamping process rules. The whole product knowledge has been represented by frames which directly map to objects (or features) in the object-oriented sense. Relevant appropriate operations features have been assigned to stamping features of a product based on feature-operation criteria, parameters of the stamping feature and their correlativity. This assignment is a decision-making activity using a set of rules with a decision-making tree and model-based reasoning methods. With knowledge between operations, such as operations order constraint (do-after) and operations combination constraint, process paths have been improved based on relevant intelligent reasoning methods. Based on the relationships (preferred-to) between processes and machines/dies, the structure of die and machine for each process can be identified, since the process route has been determined. In this stamping process planning, the procedure and information have been controlled by a process control structure that is associative and integrated. [ABSTRACT FROM AUTHOR]

Metallurgical aspects of the development of new magnesium alloys for the production of transmission parts and assemblies with the use of sand mold casting, chill casting, and high-pressure die casting are considered. The approach suggested has been used for creating new alloys with elevated creep resistance. The properties of the alloys are presented and compared with the properties of known commercial magnesium alloys. [ABSTRACT FROM AUTHOR]

A review of the literature devoted to the problem of efficiency of the use of aluminum alloys in automotive structures is presented. Requirements are formulated on the structure and properties of alloys for cold rolling of car parts. The results of a study of sheets from AV alloy with a fine-grained recrystallized structure and adaptability to manufacture, which makes the sheets suitable for automotive panels, and mechanical properties at the level of steel sheets after aging in the process of drying of the lacquer coating, are presented. [ABSTRACT FROM AUTHOR]

Standard production and machining of automotive components is still attractive, although it is not cost-effective if the life of the component has the highest priority. An important parameter to increase the fatigue life of these components is the beneficial introduction of residual stress, especially in the most loaded superficial layers. The aim of the present study is to investigate the residual stress in two steel gears produced from extruded bars cut and machined and then submitted to tempering and nitriding. The results have been compared with those obtained on sintered, nitro-carburised steel gears manufactured using the net-shape forming technique. They show a higher tensile stress level in the bulk of the component with higher carbon and chromium content, that is, a strong influence of nitriding elements. Consequently, in the nitrided layers, the calculated compressive stresses reach relatively high values in an aluminium- and carbon-rich sample. These stresses are sensibly larger than those found in the sintered and nitro-carburised gears, both in the surface and in the bulk. [ABSTRACT FROM AUTHOR]