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Abstract Numerous researchers are committed to finding solutions to the path planning problem of intelligence-based vehicles. How to select the appropriate algorithm for path planning has always been the topic of scholars. To analyze the advantages of existing path planning algorithms, the intelligence-based vehicle path planning algorithms are classified into conventional path planning methods, intelligent path planning methods, and reinforcement learning (RL) path planning methods. The currently popular RL path planning techniques are classified into two categories: model based and model free, which are more suitable for complex unknown environments. Model-based learning contains a policy iterative method and value iterative method. Model-free learning contains a time-difference algorithm, Q-learning algorithm, state-action-reward-state-action (SARSA) algorithm, and Monte Carlo (MC) algorithm.

Abstract In this article, the crashworthiness of a locomotive is assessed through finite element analysis (FEA). The present investigation is focused on the analysis of a locomotive with driving cab to improve the modeling approach and exploring the intrinsic structural weaknesses to improve its crashworthiness. The analyses are conducted according to the EN 15227 standard, which provide crashworthiness requirements for locomotive structure. The finite element model is validated in terms of acceleration and energy balance by the experimental results. The validated model is further used to assess the crashworthiness behavior at a higher impact speed, that is, 100, 160, and 225 km/hr. It has been noticed that local buckling occurs at different points, which reduces the desired progressive damage behavior in the locomotive. The results indicate that at higher speed, large plastic deformation occurs in the frontal part of the locomotive.

Abstract This article investigates the lateral dynamic behavior of a two-wheel axle bogie frame of an Indian railway vehicle. The influence of the different parameters of the vehicle on stability is investigated. The model is formulated by assigning 10 degrees of freedom (DoF) to the system with yaw and lateral DoF assigned to the bogie frame and vertical, lateral, roll, and yaw DoF assigned to each wheel axle. Linear creep force and moments suggested by Kalker’s linear theory of creep have been accounted for in the analysis. The stability analysis is carried out by transforming the second-order differential equations into first-order differential equations using state-space representation. The present model is validated by comparing the eigenvalues of the analytical model with the same obtained from the finite element (FE) model. The results obtained from the analytical and FE model are in good agreement.

Abstract Insulating combustion chamber surfaces with thermal barrier coatings (TBCs) provides thermal efficiency improvement when done appropriately. This article reports on insulation heat transfer, engine performance characteristics, and damage modelling of “temperature swing” TBCs. “Temperature swing” insulation refers to the insulation material applied on surfaces of combustion chamber walls that enables selective manipulation of its surface temperature profile over the four strokes of an engine cycle. A combined GT Suite-ANSYS Fluent simulation methodology is developed to investigate the impact of thermal properties and insulation thickness for a variety of TBC materials for its “temperature swing” characteristics. This one-dimensional transient heat conduction analyses and engine cycle simulations are performed using scaled-down thermal properties of yttria-stabilized zirconia.

Abstract During mining material hauling, the chassis frame structure of rear dump trucks is subjected to fatigue loading due to uneven road conditions. This loading often leads to crack propagation in the frame rails, necessitating the determination of stresses in the critical zone during the design stage to ensure structural integrity. In this study, a computer-aided engineering (CAE) methodology is employed to size and select the rectangular profile cross section of the chassis frame rail. A detailed design investigation of the chassis frame is conducted to assess its load resistance, structural flexibility, and weld joint fatigue life under critical stresses arising from combined bending and torsion loads. The optimization process aims to determine the optimal rail size and material thickness, striking a balance between minimizing mass and maximizing structural reliability.

Abstract The ability to predict the durability of a structure depends on the knowledge of operating loads experienced by the structure. Typically, multi-body dynamics (MBD) models are used to cascade measured wheel loads to hard points. However, in this approach, there are many sources by which errors creep into cascaded forces. Any attempt to reduce sources of such errors is time consuming and costly. In typical program development timelines, it is very difficult to accommodate such model calibration efforts. Commercial load cells exist in the industry to give engineers insight into understanding the complex real-world loading of their structures. A significant limitation to the use of load cells is that the structure needs to be modified to accept the load cell, and not all desired loading degrees of freedom (DOFs) can be measured. One of the innovative solutions to calculate operating loads is to convert the structure itself into its own load transducer.

Abstract Truck platooning comprises a number of trucks equipped with automated lateral and longitudinal vehicle control technology, which allows them to move in tight formation with short following distances. This study is an initial step toward developing an understanding of the occupant injury risks associated with the multiple sequential impacts between truck platoons and roadside safety barriers, regardless of whether the crash is associated with a malfunction of automated control or human operation. Full-scale crash impacts of a tractor-trailer platoon into a concrete bridge guardrail were simulated for a specific Test Level condition according to the Manual for Assessing Safety Hardware (MASH) standards. The model of the bridge barrier was developed based on its drawings, and material properties were assigned according to literature data.

Abstract Rubber elements present highly nonlinear mechanical properties affected by frequency and amplitude of excitation, prestrain and temperature, etc. Finite element (FE) models and lumped parameter models can be distinguished in the development of constitutive models of rubbers. Based on the concept of overlay model, different kinds of viscoelastic, or frequency-dependent models, and elastoplastic/friction, or amplitude-dependent models, are compared in terms of their modelling approach, parameters identification process and applications. Prestrain-dependent models and temperature-dependent thermo-mechanical models are also reviewed, including some special models which are not based on the concept of the overlay model. Experimental and computational studies of cylindrical bushings subjected to coupled deformation modes are analyzed and discussed.

Abstract Guardrail end terminals are specifically designed to decelerate vehicles during impact and protect vehicle occupants from severe injuries. The main objective of this research was to develop and validate a Finite Element (FE) model of the ET-Plus, a commonly used energy-absorbing guardrail end terminal. The ET-Plus FE model was created based on publicly available data on ET-Plus dimensions and material properties. The model was validated against the NCHRP-350 crash tests 27-30 and 31-30 by performing crash simulations with a vehicle model at 100 km/h (62 mph) pre-impact velocity. To check the model robustness, crash simulations with vehicle pre-impact velocities from 97 km/h (60 mph) to 113 km/h (70 mph) were also performed. The developed ET-Plus FE model has a high-quality mesh and can replicate the energy-absorbing mechanism.

Abstract This article takes the wet multi-disc brake used in mining Isuzu 600P as the research object, establishes a simplified three-dimensional model of its key components through SOLIDWORKS and imports it into ANSYS Workbench to establish the flow field and structure field model of the wet brake. Based on the fluid–solid coupling, the finite element simulation of the temperature field and stress field of the friction pair of the wet brake under different braking pressures, braking initial speeds, and fluid viscosities was carried out, and then the position changes of the friction pairs at high temperature hot spots and high stress points were analyzed to determine the stability of its friction performance. Finally, by comparing the temperature change curves of the same point during the braking process under different braking conditions, the validity of the finite element analysis results is verified.

Abstract In recent years, several buses have ignited in some cities in China, causing numerous deaths and significant property damage. However, few research studies have been conducted to deal with such accidents. Therefore, in this work, a linear-shaped charge jet with rectangular cross sections was used to hew out evacuation routes for burning buses, and the parameter design for the shaped charge jet was improved according to asymmetry limitations and human tolerance. A numerical finite element simulation model of the behavior of a jet penetrating the jambs was established using ANSYS/LS-DYNA software. The asymmetrical characteristics of an arc segment in the structure of a rectangular-shaped charge were analyzed, in addition to the influence on the deviations of the jet penetration capacity and blast injuries to occupants caused by the side effects of detonation.

Abstract This article investigates options for lightweighting truck trailers through a combination of material selection and structural optimization. Critical chassis design load cases were established, and a parametric finite element (FE) model of a typical European-style 13.5 m long truck trailer built from steel I-beams was developed. The model has been used to show that existing longitudinal steel I-beams could be reduced in weight by 28% (140 kg) through shape optimization alone. The model was expanded to analyze holistic composite trailer structures. It showed that up to 67% (1,326 kg) of weight could be saved by executing shape and material optimization in unison. The approach highlights that design through parametric analysis allows for many different structural configurations to be assessed in terms of both mechanical performance and material cost.

Abstract Since vehicle structural flexibility and suspension nonlinearity are usually not considered, many existing vehicle models have difficulty in accurately describing the dynamic characteristics of the actual vehicle, which limits their practical applications. This article presents a rigid-flexible coupled system to investigate the dynamic behavior of a heavy-duty truck. An improved Maxwell-slip (IMS) model is proposed to describe the hysteresis nonlinearity of a leaf spring. In the coupled system, the axles and powertrain are simplified to be rigid, and the cab and frame are modeled using finite element method (FEM) considering their flexibility. During the solution process, the application of the FEM leads to a significant increase in the computer burden. Therefore, the iterated improved reduction system (IIRS) method is adopted to reduce the size of the large-size finite-element (FE) models to achieve the purpose of improving the calculation efficiency.

Abstract The present article analyzes the influence of the track and rail vehicle vibrations on the biodynamic human subject. A mathematical model of 47 degrees of freedom (DoF) human body-vehicle-track vibratory system is formulated for the analysis of ride behavior of the vehicle and human body system. The human body, vehicle, and track system are assigned 7 DoF, 37 DoF, and 3 DoF, respectively, and the system is formulated using Newton’s method. Stationary random irregularities of the track are accounted for in the analysis, represented by the power spectral density (PSD) function, and are used as an input to the system. The ride comfort of the rail vehicle is examined based on the International Organization of Standardization (ISO) comfort specifications. The biodynamic human subject, vehicle, and track system are evaluated independently and integrated to examine the response of one system due to the excitation of another.

Abstract The main objective is to evaluate the level of stresses and strains in the component structure responsible for supporting the entire movable upper part of a loader crane and to indicate possible design adjustments in order to improve the product and predict possible structural problems using the experimental analysis to calibrate the numerical model that also serves as a procedure to validate the total structure and futures new similar cases. For this purpose, a nonlinear static structural analysis will be performed using the finite element method, where the system will be adjusted to a virtual environment in order to better represent the reality of the efforts and supports involved, taking into account the contacts between bushings, the mechanical properties of the materials, and also the geometric nonlinearity of the components. Validation was performed by means of an experimental analysis carried out in a test field on the final product.

Abstract In this article, a 300-ton truck crane was used as the research object, and the data and experience of telescopic boom design were integrated to optimize the design research under three dangerous working conditions of the telescopic boom. Three-dimensional (3D) modeling software and finite element software were used to model and statistically analyze the truck crane telescopic boom. Then the correctness of the finite element model was verified by static experiments, and the design was optimized. Under the condition of satisfying the strength and stiffness, the telescopic crane boom was optimized by using the response surface optimization module in Ansys workbench software to be lightweight, and more satisfactory results were obtained. Finally, through the modal and flexural analysis of the optimized model, ideas and suggestions were provided for the further optimization of the telescopic boom.

Abstract The human body models consisting of bone, soft tissue, and skin were created based on the latest anthropometry data. The mechanical modeling of vehicle seat cover was studied, as well as the simulation of human-seat interface pressure. As a case study, the seat finite element (FE) model was established using the real-vehicle seat geometric data considering the condition with and without seat cover. The seat and body were assembled to conduct the simulation of human-seat interface pressure. By comparing the simulative result with those of the test, the accuracy of the simulation and the important role of cover material in body pressure simulation were validated. The result also showed that the cover material could not be ignored in the simulation of human-seat interface pressure.

Abstract The lightweight structure of a semitrailer composite leaf spring is designed and manufactured using glass fiber composite to replace the conventional steel leaf spring. The sliding composite mono leaf spring was designed based on the conventional parabolic spring design theory. The composites product design (CPD) module of CATIA software is used to create the lamination of the composite leaf spring. Using finite element analysis of the position and proportion of ±45° biaxial layer by OptiStruct software, it is found that a certain proportion (nearly 5%) of a ±45° biaxial layer can effectively reduce the shear stress under the condition of keeping the total number of layers fixed. Then, the natural frequency, stiffness, and strength of the composite leaf spring are simulated by the finite element method. Finally, the stiffness, fatigue, and matching of the designed spring are tested by experiments.

Abstract TOC

Abstract Diesel engines include systems for cooling, lubrication, and fuel injection and contain a variety of components. A malfunction in any of the engine systems or the presence of any faulty element influences engine performance and deteriorates its components. This research is concerned with the untimely appearance of vital cracks in the liners of a turbocharged heavy-duty Diesel engine. To find the root causes for premature failure, rigorous examinations through visual observations, material characterization, and metallographic investigations are performed. These include Scanning Electron Microscope (SEM) and Energy-Dispersive Spectroscopy (EDS), fracture mechanics analysis, and performance examination, which are also followed by Finite Element Moldings. To find the proper remedy to resolve the problem, drawing a precise and reliable picture of the engine’s operating conditions is required.