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Gearbox is an indispensable element allied with mechanical industries to fluctuate speed and load in accordance with the requirements. More improvements in its mechanical structure and procedure can increase the efficiency of the industries. For those reasons, the gearbox was designed and manufactured very carefully with the zero tolerance of defects. Gearbox failure can lead to an increase in financial loss and decrease in production strength. Vibration signal analysis is used to monitor the gearbox condition. But, non-stationary properties of vibration signal make this procedure very challenging. Therefore, this paper presents a unique gearbox fault investigation technique based on advanced computational intelligence. Firstly, Time Synchronous Averaging algorithm was used to study the nonstationary properties of the raw vibration signal. Then, nine types of time domain arithmetical features were calculated from the pre-processed TSA vibration signal. After that, the J48 algorithm was used for significant features selection of gearbox fault and Naive Bayes algorithm for features classification of gearbox fault. A computer-aided fault simulator was used for experimental study. MATLAB and WEKA platforms were used for signal processing, features selection, and features classification of the gearbox faults. The performance of the proposed method shows meaningful results for gearbox fault diagnosis.

Time synchronous averaging (TSA) has been extensively applied for gearbox fault analysis. But it cannot unveil the vibration features precisely in conditions of different speeds and load excitation. This paper presents an improved method which is a combination of Time synchronous averaging (TSA) and Empirical mode decomposition (EMD) to extract the intermittent vibration feature from the oscillated vibration response for the fault diagnosis of the gearbox. In this technique, time-synchronous averaging and empirical mode decomposition is performed on the gearbox vibration response to detect fault features. First, TSA is performed on the gearbox raw vibration response. By applying TSA on raw vibration response, a noiseless vibration response with the power spectrum is produced. Finally, decomposition technique is applied on noiseless vibration response and a sequence of IMFs are produced with the power spectrum to obtain more enhanced and improved mono-component of noiseless regular vibration response. Simulation and Practical investigation of the proposed method show the advantages and effectiveness in extracting faulty vibration feature with different speed and load excitation. An experimental investigation has been carried out on the Machinery Fault Simulator with one healthy and two faulty gearbox conditions i.e., healthy tooth, fragmented tooth and missing tooth under three different speed and load excitation.

Experimental and numerical investigations are performed to evaluate the mass diffusion in Agave Americana natural fiber composites considering several environmental conditions. The effect of fiber pretreatment by alkaline hornification is analyzed on the moisture uptake behavior of the Agave fiber composites. It was observed that water retention value, which is a measure of affinity towards moisture, reduces with each subsequent hornification cycle. The microstructural investigations were performed to analyze the morphological changes in fiber microfibrils. Composite specimens were subjected to accelerated ageing under water and humidity conditions at controlled temperatures between 0 °C and 75 °C. Composites were weighted periodically and mass gain curves were analyzed. A comparison is drawn between the mass gain behavior of composites fabricated using untreated and alkali hornified Agave fibers. The studies have revealed a clear influence of alkaline hornification on the improvement of the hydrothermal durability of the Agave fibers. The effective moisture diffusivity of the composites is determined using edge correction factors for rectanguloid specimens. Finally, the experimental mass gain is compared with the numerical Fick’s law based finite element (FE) approximations.

The diffusion of moisture is an environmental factor that limits the durability of polymer composites considerably in the wet/moist environments. The present paper examines the diffusion of moisture along and across through the unidirectional natural fiber reinforced polymer matrix composites. A number of three dimensional models with different fiber orientations have been used to analyze moisture diffusion along and across the fibers. Fickian moisture diffusion theory has been used to model the mass transport along the considered composite domains. It is observed that there are several orientation of fiber that can impede the moisture ingress, whereas some of the counterpart configurations do not produce the favorable results and hence those kind of configurations can be avoided. The analysis should be helpful in designing moisture durable fiber matrix architectures.

This paper presents the effect of inter-fiber interaction among the fibers in neighborhood on the overall mechanical behavior of the reinforced polymer composites. The effect of inter-fiber interactions is presented for different classes of microstructures. Cohesive zone model is adopted to simulate the interfacial fiber matrix progressive de-bonding. Different microstructural arrangements are considered to model the transverse loading. The study highlights the role microstructural arrangement plays in the final macroscopic response of composites. The observations should help in designing the fiber matrix microstructures for superior mechanical characteristics.

Neglecting dynamic load during design of a prismatic joint for high-speed operation may lead to unpredictable failures. A slider joint is usually a part of a pneumatic or hydraulic actuation device which may further involve complicated control systems. Thus, design/analysis of prismatic joints calls for a multi-energy domain modeling approach such as bond graph for reusability of the model in different application scenarios. The slider is treated to be a multibody system composed of two separate rigid bodies which are constrained to produce the desired motion. The constraints generate the dynamic contact forces which are used to compute the dynamic frictional forces. The bond graph model of the planar slider component developed in this article accurately calculates the dynamic loads. The model is first validated through numerical simulations performed on a Rapson slide. Thereafter, a multi-energy model for a V-twin engine and its mounting is developed to show how bond graph modeling makes it possible to create an integrated model of thermal, pneumatic and mechanical systems. Finally, the bond graph model of a three-dimensional prismatic joint is developed.

Antilock braking system (ABS), traction control system, etc. are used in modern automobiles for enhanced safety and reliability. Autonomous ABS system can take over the traction control of the vehicle either completely or partially. An antilock braking system using an on–off control strategy to maintain the wheel slip within a predefined range is studied here. The controller design needs integration with the vehicle dynamics model. A single wheel or a bicycle vehicle model considers only constant normal loading on the wheels. On the other hand, a four wheel vehicle model that accounts for dynamic normal loading on the wheels and generates correct lateral forces is suitable for reliable brake system design. This paper describes an integrated vehicle braking system dynamics and control modeling procedure for a four wheel vehicle. The vehicle system comprises several energy domains. The interdisciplinary modeling technique called bond graph is used to integrate models in different energy domains and control systems. The bond graph model of the integrated vehicle dynamic system is developed in a modular and hierarchical modeling environment and is simulated to evaluate the performance of the ABS system under various operating conditions.