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Sheets’ buckling instability, also known as oil canning, is an issue that characterizes the resistance to denting in thin metal panels. The oil canning phenomenon is characterized by a depression in the metal sheet, caused by a local buckling, which is a critical design issue for aesthetic parts, such as automotive outer panels. Predicting the buckling instability during the design stage is not straightforward since the shape of the component might change several times before the part is sent to production and can actually be tested. To overcome this issue, this research presents a robust prediction model based on the convolutional neural network (CNN) to estimate the buckling instability of automotive sheet metal panels, based on the major, minor, and Gaussian surface curvatures. The training dataset for the CNN model was generated by implementing finite element analysis (FEA) of the outer panels of various commercial vehicles, for a total of twenty panels, and by considering different indentation locations on each panel. From the implemented simulation models the load-stroke curves were exported and utilized to determine the presence, or absence, of buckling instability and to determine its magnitude. Moreover, from the computer aided design (CAD) files of the relevant panels, the three considered curvatures on the tested indentation points were acquired as well. All the positions considered in the FEA analyses were backed up by industrial experiments on the relevant panels in their assembled position, allowing to validate their reliability. The combined correlation of curvatures and load-displacement curves allowed correlating the geometrical features that create the conditions for buckling instability to arise and was utilized to train the CNN algorithm, defined considering 13 convolution layers and 5 pooling layers. The trained CNN model was applied to another automotive frame, not used in the training process, and the prediction results were compared with experimental indentation tests. The overall accuracy of the CNN model was calculated to be 90.1%, representing the reliability of the proposed algorithm of predicting the severity of the buckling instability for automotive sheet metal panels.

A buckling of the thin plate after stamping process is called an oil canning phenomenon. This issue impacts the shape and induces vibration and noise effects on the outer surface of the stamped parts such as the automobile and white-good products. To answer the call for reducing the oil canning, the results of a number of experimental procedures carried out on two largely utilized steel, namely the AISI-1008 and AISI-1020 steel alloys are used to define an empirical-numerical model for the prediction of oil canning in the design stage. The results of the tests on those two steel are utilized for the definition of the process parameters which can be directly linked to the rise of the oil canning phenomenon on metal sheets. Accordingly, in this paper, the thickness, the curvature radius, the length, and the width of the panel are considered the most influencing parameters in the arising of oil canning issue. A stamping process is carried out, and an indentation test is applied to check the oil canning on the stamped sheets. In addition, the measurements on assigned points on the stamped panel for thickness and curvature radius are carried out. Afterward, based on the experimental results, numerical simulations have been implemented in LS-Dyna and the results are utilized for the definition of an oil canning index (OCI) model that is used to define the higher or lower risk of oil canning occurrence when a certain combination of material and process parameters are utilized. In the proposed model, an OCI close to zero defines a condition where oil canning is unlikely to happen whereas an OCI close to one or higher stands for high risk of oil canning to arise. The obtained oil canning values are correlated with the curvature radius results which found to be the most considerable effect on the oil canning occurrence.

In roll forming a wide flat channel, problems were experienced with wrinkling, or ‘oil canning’ in the web. This is a common shape problem in roll forming wide panels that have flat regions in the profile. Coils from four different suppliers were used in production; with three of these, wrinkling could be controlled, but one coil had to be discarded. Tensile tests performed on all materials did not identify major differences in the coils although one material showed a slight indication of ageing. Free bending tests were performed with a new stand-alone bend tester specifically developed for material characterisation on the shop floor. The bending tests performed on strips cut in the longitudinal direction showed a greater difference between coils; the material giving unacceptable wrinkling had a significantly higher moment curvature characteristic indicating substantial ageing. All materials showed some coil set and the bending properties depended on the direction in which the specimen was bent, i.e. in the same or opposite direction to the coil set. A finite element analysis was performed on the process which indicated significant plastic deformation in the flange, but very little in the web. Possible links between the unusual bending behaviour and oil canning in the web are suggested and the work indicates the desirability of performing free bending tests in addition to the customary tensile testing in roll forming applications.

The research presented in this paper deals with the development of a numerical-empirical-based model for the estimation of the indentation stiffness of automotive body panels, implemented in a self-developed simulation program for the quick and precise evaluation of the denting performances of newly developed parts during the design stage. The stiffness of the panels is estimated by calculating the major and minor curvatures, and their relevant variations, and can be applied also in the early stages of the design process, with no need for numerical simulations of the forming process required for the manufacturing of the panels. The model has been developed on the basis of a large number of indentation experiments carried out on existing automotive body panels (fender, front door, rear door, roof and hood) belonging to four different vehicle models. From the experiments, the load-stroke curve has been compared with the reference one (provided by the panels manufacturer) and the ratio between the integral area of the relevant experiment, and that of the reference curve has been defined as the stiffness index (SI). For all the tested specimens, between 18 and 24 points have been tested by means of indentation test whereas additional 20 points have been tested by means of numerical simulations, implemented in ABAQUS/Standard, in order to add additional data for the definition of the empirical model. The implemented numerical model has been initially validated by comparison its results with those of the laboratory experiments, showing a maximum error equal to 10.8%. Moreover, in order to account for the oil canning phenomenon (local softening), a penalization factor has been introduced in the model and has the effect of reducing the local SI values for the considered point of the panel. The regression model for the SI function has been calculated by utilizing the commercial software MINITAB with a correlation factor (R2) higher than 92%. Finally, the developed model has been implemented in a self-developed simulation program which allows imputing the CAD file of the panel and, within few minutes, to estimate the SI distribution on the part on the basis of the local curvatures (major and minor) and on the curvature variation calculated on the whole model.

Lubricating oils are widely used to reduce friction and wear by interposing a film of material between rubbing surfaces. However, the used lubricant oil does not evaporate and less subject to biodegradation. It requires proper treatment before it can be discharged to the environment. Recently, there is an increase tendency of using used lubricating oil as re-refining feedstock on a worldwide basis. Re-refining of used lubricating oil is an intelligent option for any country, more so for India, as it would conserve both the natural resources as well as foreign exchange. It would also make us near self-reliant in lube oils.

The buckling point detected at the Yoshida Buckling Test is at an extremely low strain level, which does not reflect the reality observed in stamping of complex parts. A new buckling test, “Contact Buckling Test”, is proposed here with the thought that the delay of buckling in reality is due to the existence of sheet curvature and the contact support provided by tooling. Interesting buckling phenomena have been observed for both aluminum and steel sheets, including oil canning, buckling at the loading stage, and buckling at unloading. The fundamentals of these different buckling phenomena will be explained through a stress-based wrinkling predictor developed by the authors.

A parametric study of the factors controlling static and dynamic denting, as well as local stiffness, has been made on simplified panels of different sizes, curvatures, thicknesses and strengths. Analyses have been performed using the finite element method to predict dent resistance and panel stiffness. A parametric approach is used with finite element models of simplified panels. Two sizes of panels with square plan dimensions and a wide range of curvatures are analysed for several combinations of material thickness and strength, all representative of automotive closure panels. Analysis was performed using the implicit finite element code, LS-NIKE, and the explicit dynamic code, LS-DYNA for the static and dynamic cases, respectively. Panel dent resistance and stiffness behaviour are shown to be complex phenomena and strongly interrelated. Factors favouring improved dent resistance include increased yield strength and panel thickness. Panel stiffness also increases with thickness and with higher curvatures but decreases with size and very low curvatures. Conditions for best dynamic and static dent performance are shown to be inherently in conflict ; that is, panels with low stiffness tend to perform well under impact loading but demonstrate inferior static dent performance. Stiffer panels are prone to larger dynamic dents due to higher contact forces but exhibit good static performance through increased resistance to oil canning.

In the interest of improved automotive fuel economy, one solution is reducing vehicle weight. Achieving significant weight reductions will normally require reducing the panel thickness or using alternative materials such as aluminum alloy sheet. These changes will affect the dent resistance of the panel. In this study, the correlation between panel size, curvature, thickness, material properties and dent resistance is investigated. A parametric approach is adopted, utilizing a “design software” tool incorporating empirical equations to predict denting and panel stiffness for simplified panels. The most effective time to optimize an automotive body panel is early in its development. The developed design program can be used to minimize panel thickness or compare different materials, while maintaining adequate panel performance.

In the conventional system of lubrication, lubricating oil is renewed with fresh oil after it is used for some period. Accordingly, waste oil is generated in the conventional system. The authors have developed a new system that makes it possible to use lubricating oil semi-permanently without oil renewal. In the new system, therefore, no waste oil is generated and it is enough to supply only a small amount of fresh oil sometimes to compensate for the lost oil. This system has been working well in about one thousand units of marine and cogeneration diesel engines in practice. The new system always keeps lubricating oil clean as the kidney of animals always keeps their blood clean. This is why lubricating oil can be used semi-permanently and the new system is called kidney system. This technology has been developed based on the assumption that lubricating oil is hardly oxidized contrary to the general knowledge all over the world. This report verifies the above mentioned assumption based on our analysis of used oil in engines in practical use and some data in various fields.

In the conventional system of lubrication, lubricating oil is renewed with fresh oil after it is used for some period. Accordingly, waste oil is generated in the conventional system.The authors have developed a new system that makes it possible to use lubricating oil semi-permanently without oil renewal. In the new system, therefore, no waste oil is generated and it is enough to supply only a small amount of fresh oil sometimes to compensate for the lost oil. This system has been working well in about 1000 units of marine and cogeneration diesel engines in practice. The new system always keeps the lubricating oil clean as the kidney of animals always keeps their blood clean.This is why lubricating oil can be used semi-permanently and the new system is called kidney system.This paper reports the theory, the process of R&D and the results of practical use of the new technology.

Fiber glass reinforced composites like sheet molding compounds (SMC) have recently been widely used in the fabrication of two-piece automobile hoods for passenger cars. In the present investigation, a one-piece composite hood with reinforcing ribs was optimally designed and manufactured by resin transfer molding in order to reduce manufacturing cost. In order to obtain the optimal design, stiffness analyses for deflections due to self-weight, oil canning, and torsion test conditions were carried out by applying the ABAQUS/Standard program. Based on these analyses, the thickness dimension of the composite hood required to maintain a stiffness comparable to a conventional steel hood was determined. For optimization studies of the weight reduction of the currently proposed one-piece composite hood with reinforcing ribs, IDESIGN program was employed. Based on a recursive quadratic programming technique, the thickness dimensions of the reinforcing ribs were optimized. The deflection ratios between fiber glass reinforced composite and conventional steel hoods were minimized in the optimization studies. From the present studies, it was found that the weight saving effect obtained by introducing the optimally designed one-piece composite hood was 37% compared to the conventional steel hood. This ranged approximately from 30 to 40% for composite hoods manufactured by resin transfer molding, depending on the composite materials used. Through these studies, it was confirmed that the one-piece composite hood was a preferable design and manufacture, compared to currently used composite hood made in two pieces, in terms of weight reductions and manufacturing cost without losing the stiffness required.

From test studying, it indicates that the lower strain magnitude and non-homogeneous strain distribution are the causes of oil canning in large flat/sweep areas of stamping product. In order to eliminate oil canning defect, the minimum equivalent strain in deformation zone should be greater than 2 % and the strain gradient be as small as possible. The prediction approach was proposed for oil canning problem based on strain gradient and equivalent strain magnitude, and the approach was integrated into KMAS-UFT software aiming at predicting oil caning problem by CAE analysis. The paper takes hood outer panel as an example and carries out CAE analysis. It is confirmed that the prediction approach is both accurate and effective.

Manufacturing is currently being used as a continuous quality improvement tool, providing a planning, implementing, monitoring and evaluating framework for the quality improvement measures on a sustainable basis. A cause-and-effect diagram, also known as an Ishikawa diagram or fishbone diagram, is often used in quality management in manufacturing industries. Fishbone diagram (also known as Ishikawa diagram) was created with the goal of identifying and grouping the causes which generate a quality problem. Gradually, the method was used also to group into categories the causes of other types of problems which confronted an organization. This made fishbone diagram to become a very useful instrument in the risk identification stage. In this paper, the six sigma technique and cause-and-effect diagram is used to demonstrate how to relate potential causes of a major presenting problem in Sepahan Oil Company. For this purpose, the four liter production line of the company has been selected for investigation. The findings imply that the application of cause-and-effect diagram has reduced the scraps from 50000 to 5000 ppm and has resulted in a 0.92% decrease of the oil waste. Key words: Cause-and-effect diagram, Sepahan Oil Company, canning, waste, six sigma.

This text based on the scattering principle of lubricating oil to near-infrared light, fully used the computer monitor technology, designed the plan of making use of near-infrared light to monitor automobile lubricating oil, and hereby it to monitor the deteriorated condition of lubricating oil. The experiment has proved that: this kind of technology for monitoring automobile lubricating oil can satisfy the deterioration condition monitor demand of automobile lubricating oil, and can give the instructions of the lubricating oil deterioration degree, so we can decide whether the lubricating oil can continue to use according to it. This method changed the traditional conditions that replace the lubricating oil according to time or the travel course number, it realized replacing lubricating oil according to the quality, thus it make the lubricating oil obtain the reasonable economy service life, and guaranteed the good lubrication condition of vehicles.

Due to the application of thinner sheet steels, the stamped panels in the forming process, generally, are severely distorted. The wavy shape of embossed panel finally converted to residual stress embedded in the panel at final forming (edge L‐bending) and it is known as the cause of twisting and oil canning of spring backed panel. Another important source of stamped shape deviation is the curvature of blank. The effects of blank curvature on the shape defects (panel curvature and twisting) after stamping were investigated from defective panel analysis, model experiment and stamping simulation. And the effect of tool conditions (BHF and bead height change) on spring backed shape of real TV bottom chassis were studied. The initial curvature of blank was remained in the flat area of stamped panels as width directional curvature. It converted from length direction curvature of blank. The curvature of initial blank reduced the wavy shape after local emboss forming, but twisting after edge L‐bending was increased at large blank curvature cases. The effects of emboss forming conditions, the forming heights and blank holding force were studied and it was found that the wavy shape of stamped sheet was rapidly changed although the forming conditions altered very small amount.

With the decrease of sheet thickness, the stiffness and buckling behavior of automobile body panel are more and more concerned. In this paper, the stiffness and buckling behavior of panels with stamping‐induced imperfection is studied. Imperfections caused in drawing and springback are obtained by finite element analysis and introduced to define the initial state of the panel before indenting. The indenting procedure is simulated in ABAQUS Standard. In order to solve the buckling problem, a viscous pressure that is proportional to the relative velocity between surfaces is added artificially. For comparison, a simplified model in which imperfections are not considered is also established. Comparing the simulation results with the reference experiment, we find that the stamping‐induced imperfections lead to a more severe oil canning phenomena under a buckling load, although they increase panel’s initial stiffness a bit. Moreover, among all stamping‐induced imperfections, the geometrical imperfection (surface deflection) is beneficial to increase panel’s buckling load, and the material imperfections (residual stress and uneven thickness) help to decrease panel’s buckling load and can make oil canning more severe during post‐buckling. Influences of blank holder force, sheet thickness and material property on panel stiffness and buckling behavior are also studied. The work of this paper is beneficial to processing optimization, material selection, and reinforcement design for automotive exterior panels.

Recently, significantly thinner sheet steels are tested and applied in digital display equipment than previous ones, therefore many cases of shape defects such as twisting, oil canning and curvatures in stamped panels are reported from stamping factories. In order to study the cause of twisting defects of stamped panel, simulative tests by 800×500 and 240×180 size blank and numerical simulation were done and analyzed the effects of forming conditions and material characteristics on twisting defects. It was found that the residual stress in stamped panel is the source of twisting and it increases as the difference between residual stress in panel center (positive stress component due to emboss forming) and marginal regions (negative stress value) increases. Both the residual stress difference in blank and twisting deformation increased in dense emboss formed cases than sparse embossing cases. Twisting deformation was increased if thinner blank, more curved blank and higher yield stress sheet applied cases.

This study has been designed to investigate the concept that the passage of red blood cells (clearly seen “bulging” into the air space in all scanning electron micrographs of the alveolar surface) can produce a net force tending to return any excess fluid to the interstitium. Measurements of surface tension over the time frame and probable surface area excursion incurred by a passing red blood cell show an appreciably higher value corresponding to the expanding surface, which is convex with respect to air, than when it is compressing and concave. The mean difference in surface tension of about 16 dyn/cm (mN/m) translates into a net driving force of approximately 6 mmHg induced by this rapidly alternating microcurvature reflecting the highly dynamic state of the living alveolar wall. The significance of the microcurvature of the alveolar surface is emphasized in relation to surfactant function.

Web-buckling, sometimes called pocket wave or oil canning, is one of the typical defects which take place in a cold roll-forming process of wide profiles. The relations between web-buckling appearance and several properties of commercially pure titanium sheets were experimentally investigated. Results showed that the grain size is most correlative to web-buckling, and that the magnitude of pocket wave tends to decrease with decreases in the grain size. The mechanism of inhibiting web-bucking in fine-grained titanium sheets is considered to be the fact that deformation must be localized at bend corners of formed profiles, as those titanium sheets reveal clear yield drop at the start of plastic flow.

Between April 15 and June 14, 1993, Archaeological Research Services, Inc. performed a cultural resources survey of State Route 88 (the Apache Trail). The right-of-way varies from 66 to 200 feet, but construction as-builts were not available. Therefore, the Arizona Department of Transportation requested that a 200 foot wide right-of-way be surveyed for the entire project length unless clearly marked property boundaries or other right-of-way indications were present. The 17.5 mile long survey corridor crosses lands owned by the Arizona Department of Transportation, and sections of Arizona Department of Transportation right-of-way across Bureau of Land Management lands. That segment of State Route 88 on Tonto National Forest lands was constructed through the provisions of a Special Use Permit issued to the Arizona Department of Transportation by Tonto National Forest. The survey was conducted under the conditions and authority of a Tonto National Forest special use permit issued to Archaeological Research Services, Inc. on 2/17/93, Arizona State Museum general permit number 93-11, and Bureau of Land Management permit number AZ-000054 issued 10/13/90 (fieldwork authorization number PDO-93-5, 3/23/93). The project area encompasses approximately 424.24 acres, of which approximately, 371.21 were actually surveyed when the existing paved surface of State Route 88 is excluded. The Arizona Department of Transportation requested the survey (Arizona Department of Transportation Project No. STP-952-4(1), Tracs PN 195 H3275 01C) in anticipation of a proposed pavement preservation project. Archaeological Research Services performed a Class III (Intensive Field Inventory) survey in order to locate and record any cultural resources that could be disturbed as a result of the proposed undertaking. This study provides descriptions and National Register eligibility evaluations for cultural resources encountered during the survey. As a result of the survey, 22 archaeological sites (4 previously recorded, 18 newly recorded) and 49 isolated artifact occurrences or cultural features were recorded (or rerecorded or relocated). This is the second revision of this document, with earlier versions completed 29 June 1993 and 15 November 1994.

The Bureau of Reclamation (Reclamation), United States Department of the Interior, was in the initial stages of the Water Management Project designed to bring Central Arizona Project water to the Gila River Indian Community (GRIC). Under terms of a contract signed in 1992 with the GRIC, facilities designed and constructed by Reclamation would deliver 173,000 acre-feet of water annually onto the reservation. Federal law mandates consideration of potential impacts of such projects upon cultural resources and requires that necessary and appropriate steps be taken to mitigate those impacts. In accordance with these laws, Reclamation did a complete inventory of all cultural resources that may fall within the project area. Data resulting from this inventory provided the basis for assessment of the significance of the resources and for the design of plans to mitigate potential impacts to them. Two survey areas in which a water delivery system and associated features (such as dikes) will be constructed were identified by Reclamation. Broad survey areas were defined so the location of eligible sites would be known before specific project design began. In total, 180 sites were identified and recorded during survey. These sites include possible Archaic period materials, a wide range of prehistoric Hohokam site types representing all periods of the Hohokam sequence, possible Protohistoric manifestations, and numerous Historic Pima sites of varying ages. The report consists of two volumes. Volume 1 contains background information; consideration of survey and recording methods; analyses, evaluation, and interpretation of collected data; and recommendations for future treatment of discovered sites. Volume 2 contains site descriptions.

The buckling of a round tube or curved A plate under axial compression is an example of that class of instability in which the initial buckled form becomes itself at once unstable. As a result the buckle immediately develops to a large amplitude, often with loud noise. This class of instability has been aptly termed “oil canning” from a familiar example.Thorough investigation of oil canning problems must always be tedious. As for any buckling problem it is essential to use large deflection theory and, since the amplitude of buckle rapidly becomes large, it is necessary also to consider in detail the distribution of the membrane (or mid-plane) stresses due to the buckle. This necessity, in combination with peculiar buckled forms, renders the complete solution even for a tube extremely difficult and tedious. Moreover, since the buckled form for a complete tube does not accord at all well with the edge conditions for a curved plate, the full analysis for the latter is almost prohibitively difficult.

The most effective time to optimize an automotive body panel is early in its development. A full size clay model is one of these initial stages. The computer program developed minimizes the panel thickness and still maintains corporate quality levels. Stiffness, dent resistance, oil canning, and spring-back are the corporate quality requirements considered in this analysis. The program also generates weight and cost ratios for alternate material comparisons. This technique will not only reduce cost and weight, but also help guarantee customer satisfaction.

15 mi of Extra High Voltage transmission line corridor, 2 mi of access road, and 0.9 mi of 115kV transmission line from the Silverking Substation were surveyed for archaeological resources by the Museum of Northern Arizona in April, 1978. Twelve prehistoric and historic Anglo-American affiliation archaeological sites were identified along the EHV corridor between the Silverking Substation and the Tonto National Forest boundary. An isolated recent feature, not given a site designation, was found on the proposed access road alignment. No sites were found on the 115kV alignment. The report describes the survey and its results and makes detailed archaeological clearance recommendations for the surveyed impact areas. Archaeological clearance is recommended for all surveyed areas except for the actual areas of the 12 recorded sites in the EHV corridor.

The stability of some transversely loaded nearly flat structures on hinged supports is studied, assuming the material to be subject to creep. It is shown that a sudden jump in the equilibrium configuration will occur after a certain time, due to simultaneous compression and bending of the structure.