Transmission noise directly influences the comfort of the entire vehicle. This paper reviews the existing transmission noise control techniques, and introduces the mechanism and transmission path of high-frequency whine noise, mid-frequency clashing noise and low-frequency vibration noise according to the noise frequency characteristics. Research shows that optimizing the transmission housing structure and applying sound-absorbing materials can reduce the radiation of whine noise. Micro-texturing of gears is efficient and cost-effective for improving gear whine noise, and is expected to be a future research hotspot. Adjusting torsional characteristic parameters and reasonably increasing the drag torque of idler gears can effectively suppress clashing noise. The influence of temperature on gear deformation needs to be considered in future studies. The dual-mass flywheel performs well in controlling engine speed fluctuations, and future research can focus on improving the design of the dual-mass flywheel and optimizing the engine calibration program. Changing the natural frequency of the housing and optimizing gear parameters are effective approaches to reduce vibration noise, however, there are fewer methods controlling oil pump and strap vibration noise, and the influence of lubricating oil on vibration noise should also be considered. The application of future high-efficiency and high-precision transmission noise control technologies will rely on the support of intelligent optimization algorithms.

To reduce the raw material cost of automobile painting shop, this paper proposes a plan to reduce the material consumption of electrophoretic coating, weld seam sealant, lacquer, varnish, polystyrene foam, wax, etc. Taking PVC material consumption reduction of a paint shop as an example, this paper, by analyzing the source of material waste, proposes the methodology of material waste reduction by increasing the utilization of material per bucket in aspects of equipment, process, quality, etc., reducing the manual glue application when changing bucket and reducing glue application amount of robot during production, which reduces the material consumption per vehicle significantly and reduces material cost.

In order to realize the lightweight of auto body, the traditional one-piece BIW dashboard panel is designed into two parts (the upper one and the lower one) with different thickness. According to the typical features of the front dashboard panel, namely the arch shape of the evacuation area of the wheel cover, this paper proposes shallow drawing plus reshaping to simplify stamping process and greatly improve material utilization rate. In order to address the issues of corrugation of dashboard upper panel, insufficient stiffness of single part and poor welding of evacuation area of the wheel cover, the paper verifies the feasibility of shallow drawing plus reshaping through stamping CAE analysis, stamping physical production and welding quality verification. The cost saving advantage of split-type front dashboard panel is confirmed by the cost accounting of the whole process chain (stamping, welding, coating). Finally the low-cost front dashboard panel is put into mass production with shallow drawing plus reshaping process.

This study systematically investigates the pressure-bearing capacity and failure mechanism of air suspension reservoirs through numerical simulation, burst testing, and theoretical calculation. Based on nonlinear material constitutive relations, numerical simulations reveal that when the cylinder wall thickness increases to 2.3 mm, the maximum equivalent plastic strain reaches 6%, demonstrating sufficient strength to withstand the design pressure of 6 MPa. Burst tests show the actual pressure-bearing of the 2.3 mm thick reservoir reaches 7.29 MPa, with failure consistently occurring at the nozzle-joint area, correlating perfectly with high-stress zones identified in simulations. Fracture surfaces exhibit continuous tearing morphology, confirming typical ductile fracture characteristics. Comparative theoretical calculation indicates the mean diameter formula achieves merely 2.2% deviation from experimental results, significantly outperforming the Faupel formula, thus validating its superiority for burst pressure prediction in thin-walled reservoirs.

To optimize drawbead parameters in stamping processes, a simulation model is established by using Autoform, with the resistance coefficient as the evaluation criterion. Orthogonal testing and variance analysis are employed to investigate the influence laws of 9 parameters on drawbead resistance. The results reveal that parameters such as the top fillet radius on the inflow side of the concave drawbead and the height of the convex drawbead significantly influence drawbead resistance, while the wall angle and bottom corner radius have minimal impact. In engireering, regulating the key parameters can reduce defects such as wrinkling and cracking, thereby improving mold debugging efficiency and lowering production costs.

Based on the analysis of the fracture surface and energy spectrum of the fractured bolt sleeve in the road test, it is determined that the fracture failure mode is delayed cracking. Furthermore, from the aspects of metallography and hardness, it is found that improper welding process led to the formation of medium carbon martensite in the bolt sleeve, and high hardness is the main reason for delayed cracking. The problem of high hardness of the bolt sleeve is solved by improving the welding technology of the bolt sleeve. The improved bolt sleeve is subjected to metallographic and hardness testing again. The martensite content and hardness of the improved bolt sleeve are reduced to a reasonable range. The problem of delayed cracking of the bolt sleeve is effectively controlled.

Improper handing of the power batteries of New Vnergy vehicle (NEV) throughout the life cycle will cause environment pollution and waste of resources. This paper discusses the current status of environmental protection technology for NEV power battery in terms of current materials selection, recovery systems and policy support. It also explores the development direction of power battery environmental protection technology from 3 aspects of innovation of materials, upgrading of recovery systems and follow-up of support policies.

In order to explore the influence of bio-based plasticizers and leather structure on the properties of Polyvinyl Chloride (PVC) leather materials for automobiles, system test and performance test are conducted to find that using suitable eco-friendly bio-based plasticizers for automotive interior PVC leather can meet requirements such as -10 ℃ and 30 000 times folding durability for automotive interior PVC leather materials. PVC leather using environmentally friendly bio-based plasticizers instead of petroleum-based plasticizers has green ecological and skin-friendly comfort properties, and emission of volatile organic compound and aldehyde-ketone substances is significantly lower than that of ordinary PVC leather for automotive interior, which has remarkable low-volatile and environmental protection advantages.

To ensure the purity during the aluminum alloy alloying process, it is necessary to control the impurity content in primary alloy ingots. The contents of silicon, iron, copper, aluminum, manganese, and nickel impurities in primary magnesium ingots are determined using Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) and X-Ray Fluorescence spectrometry (XRF). For ICP-AES, samples are dissolved with hydrogen peroxide-hydrochloric acid, and the spectral lines are optimized along with the matrix-matching method, achieving a detection limit of 0.000 01%~0.000 27%, a spike recovery rate of 92%~102%, and a repeatability RSD of <2.3%. For XRF, the optimal analysis conditions are determined, with a detection range of 0.000 1%~0.100 0% and a repeatability RSD of ≤3.1%. The results indicate that both methods exhibit good accuracy and repeatability, with ICP-AES offering higher sensitivity, while XRF is more suitable for rapid and non-destructive testing.

Taking 220 MPa grade ultra-low carbon bake-hardening steels as the research object, this paper compares and aralyzes test steel with Nb single-addition (H220BD-1) and Nb+Ti dual-addition (H220BD-2) systems. Through solid solution carbon calculations and internal friction method determination,the paper explores the influence of solid solution carbon on aging behavior under different composition systems, and combines with microstructure griain size characterization to elucidate the correlation mechanism between grain dimensions and Bake-Hardening (BH) value with aging resistance. Results demonstrate that Ti addition significantly reduces solid solution carbon content, effectively suppressing dynamic carbon segregation during aging. The dual-addition system achieves grain refinement, enhancing strength via Hall-Petch effect while improving aging stability.

In order to promote the practical application of chemical micro-foaming polypropylene material as a lightweight means, this paper firstly discusses the application feasibility of chemical micro-foaming on door interior panels in terms of material property definition, structural design, CAE simulation and mold flow analysis. Then， differences between conventional injection molding and chemical micro-foaming injection molding are compared. Finally， the structure design and process requirements of chemical micro-foaming products based on core-back process is proposed, and the application of chemical micro-foaming process is prospected.

To address the issue of cooling water leakage in resistance spot welding, this paper analyzes the interface between the electrode cap and the electrode arm. Through microstructural analysis and hardness gradient analysis of the adhesive material on the electrode arm, it is found that for copper alloys of different materials under the combined action of electric fields and pressure, the copper alloy with lower strength undergoes strengthening. This strengthening phenomenon leads to adverse effects in the application of automotive BIW welding.