For the friction stir welding of 3 mm thick 6005A-T6 aluminum alloy in a lap joint configuration, this paper investigates the effects of varying pin lengths and lap positions on the performance of the welded joints. The results show that the internal quality of the lap joint is sound. When the length of the stirring needle is constant, the tensile load of the weld when the lap plate is on the back side is higher than that when the lap plate is on the forward side. However, the length of the stirring needle has a great influence on the metal flow state inside the butt joint. When the butt plate is located on the backward side, the hook defect is connected to the S line; when the butt plate is located on the forward side, the hook defect presents a hook shape along the welding core area and the boundary line of thermal influence; when the butt plate is located at a certain position and on the backward side, the hook defect is connected to the welding core area. The maximum breaking load of the weld is 28 592.9 N when the length of the stirring needle is 3 mm, and the minimum breaking load of the weld is 23 514.7 N when the length of the stirring needle is 5 mm.

Based on Simufact Forming software, the rivet die selection and performance analysis of Self-Piercing Riveting (SPR) joining between DC01 steel sheet and die-cast magnesium alloy AM50A are investigated. The results show that the trapezoidal die exhibits better crack resistance compared with the flat-bottom die and the spherical die. Focusing on the trapezoidal die, the simulation model obtained through iterative optimization accurately predicts the joint forming process and failure modes under cross-peel and tensile-shear loading conditions. Furthermore, the simulated load-displacement curves, peak load and absorbed energy are highly consistent with the experimental results. The "process simulation-performance prediction-experimental validation" research framework established in this study can effectively support the rivet die selection and optimization for steel-to-magnesium SPR process, where the simulation method holds core value in crack resistance analysis, failure mode study and joint performance prediction.

To investigate the mechanical properties and failure modes of Self-Piercing Riveted (SPR) joints between steel sheets of varying strength grades and THAS cast aluminum alloy, quasi-static comparative tests are conducted under different overlap configurations and loading conditions. The results indicate that sound SPR joint quality is achieved through appropriate process design and optimized rivet-die selection, with the minimum residual bottom thickness and left/right interlock values remaining within acceptable limits. For qualified SPR joints, the peak loads under cross-tension, combined shear-tension, cross-tension peeling, and lap-shear loading conditions all increase with rising steel sheet strength, while the dominant failure mode transitions progressively from steel-side failure to aluminum-side failure. Under cross-tension loading, the peak load follows a descending order: pure cross-tension, combined shear-tension, and cross-tension peeling. Additionally, the lap-shear strength of single-rivet joints with linear overlap exceeds that of spot-welded joints employing steel sheets of equivalent grade.

Taking aluminum alloy adhesive-bonded blind riveting hybrid joints as the research object, this paper investigates the shear mechanical properties of single/double lap double-rivet adhesive-bonded blind riveting joints with different adhesive layer thicknesses and rivet arrangements. The results show that regardless of transverse or longitudinal rivet arrangement, the failure sequence of the joints uniformly initiates with cohesive failure of the adhesive layer. The rivet arrangement has no effect on the second peak load corresponding to rivet failure, while the overall failure load of transversely arranged joints is higher than that of longitudinally arranged counterparts. For single lap double-rivet joints, pull-out failure of rivets follows; for double lap double-rivet joints, the middle aluminum alloy sheet of the specimen undergoes irregular fracture subsequently. Within the test scope, the adhesive layer thickness has no significant influence on the overall failure mode of the joints. The findings can provide experimental basis for the structural design and engineering application of aluminum alloy adhesive-bonded blind riveting hybrid joints applied to vehicle bodies.

To address the cracking problem during Self-Piercing riveting (SPR) on AlSi10MnMg die-cast aluminum shock towers, a combined experimental and numerical approach is employed to investigate crack initiation and propagation behavior. Optimization is conducted from 3 perspectives: the riveting process, material composition, and die-casting process. The results indicate that riveting cracking is induced by the tensile stress in the lower sheet and the compressive stress in the adjacent region, while the low elongation and porosity defects of the cast aluminum make it prone to crack initiation. A contoured riveting die reduces plastic deformation and tensile stress; Sr modification treatment optimizes the eutectic Si morphology and increases elongation; and optimizing the runner, overflow, and die temperature reduces casting defects, thereby lowering the cracking risk.

Taking the rare earth magnesium alloy as the research object, an organic-inorganic composite passivation film is prepared by using silane-modified trivalent chromium passivation solution. To investigate the effects of process parameters such as silane concentration and passivation time on the quality and performance of the film, micro-morphology, film thickness, adhesion strength, and neutral salt spray tests are conducted. To investigate the influences of process parameters such as silane concentration and passivation time on the quality and performance of the film, microscopic morphology, film thickness, adhesion force and neutral salt spray test are conducted. The results show that the synergistic mechanism between silane and trivalent chromium could effectively fill the defects of the film, improve the compactness, and thereby enhance the corrosion resistance. The silane concentration is a key factor influencing the density of the film. When the silane concentration is too low, the three-dimensional network structure formed through cross-linking could not fully fill the pores of the passivation film, resulting in limited protective effect; while a reasonable silane concentration is conducive to the formation of a dense and uniform passivation film, effectively blocking the corrosive medium. Compared with not adding silane, the annual corrosion rate of the sample decreases by 65.97% (0.211 mm/a), but the duration of the passivation treatment needs to be controlled to avoid the slight dissolution of the passivation film in the trivalent chromium passivation solution, which would subsequently reduce the protective performance.

The new automotive seat cushion is designed based on the optimization definition of seating comfort composition materials, to solve the challenge effectively of the balancing soft comfort and stable support, as well as the static comfort and dynamic comfort. A comprehensive evaluation of the seat cushion's static and dynamic seating comfort is carried out by means of a combination of objective testing and subjective ratings. The results indicates that the optimized design offers a wider and more soft support for the hips, flanks, and thighs accompanied by a pressure distribution aligning with the physiological characteristics of seated posture. In subjective evaluation,, all scores of optimized design are higher compared to the conventional design, Among them, the indicators of bottoming sensation and vertical vibration absorption increased from 6 and 7 points to 7.25 and 8 points, respectively, demonstrating significant improvement. The optimized design could balance soft comfort experience and stable support performance, achieving a synergistic improvement in both static and dynamic comfort. This design approach provides a reference for the optimization design and evaluation on seating comfort of automobile seats.

To address the issues of low efficiency, high cost, and insufficient data reliability in the on-road test method for dynamic monitoring of the On-Board Diagnostic (OBD) system of heavy commercial vehicles under the China VI emission standard (GB 17691—2018), a dynamic OBD torque and speed limitation verification system based on Hardware-in-the-Loop (HiL) and signal virtual injection technology is proposed. By constructing a collaborative test platform composed of a chassis dynamometer data acquisition device (K - BOX), a high-precision urea level simulator, a multi - protocol OBD diagnostic module, and automated test software, closed - loop verification of the torque and speed limitation strategies of the Engine Control Unit (ECU) under abnormal urea level conditions is achieved. Currently, this technology has been successfully applied to 3 models of light and heavy commercial vehicles of a certain vehicle manufacturer.

To address charging detection failures in a new energy commercial vehicle, the system analyzes the causes of issues such as Vehicle Identification Number (VIN) mismatch, single-gun charging failure, timeout of the Battery Management System (BMS) Charging Ready Message (BRO), and timeout of the BMS Stop Message (BST). Based on in-depth fault analysis, the process of translating analytical conclusions into specific, actionable process parameters is elaborated, thereby optimizing and establishing a standardized production line charging detection procedure. This procedure defines seven process steps, from delay waiting, VIN identification, and single/dual-gun charging tests to status switching, along with their critical time parameters, ensuring the comprehensiveness and efficiency of the detection work.

Commercial line laser scanners for cross-section measurement in the automotive industry predominantly employ full cross-section fitting. In scenarios characterized by strong straight-line features of double parallel cross-sections, this approach introduces redundant computation, and the closed algorithms are difficult to adapt to the dynamic optimization requirements of production lines. To address this issue, specifically for such scenarios, the Hough transform is introduced to directly detect local straight-line features, based on the camera calibration, image filtering, and laser centerline extraction techniques associated with the light-section method. While maintaining measurement accuracy, this strategy substantially reduces measurement time, achieving a profile measurement error of ≤0.15 mm for double parallel cross-sections and effectively improving the automated measurement level of car body cross-sections.