This study takes 40 A·h square-shaped ternary lithium-ion battery as the research object to study their gas generation characteristics after thermal runaway, and uses Accelerating Rate Calorimeter (ARC) and thermal runway gas generation performance test equipment dedicated for large capacity lithium-ion batteries to determine parameters like intensity of pressure and temperatures inside the heat & gas generation unit after thermal runway. Gas production process is introduced based on the widely used thermal runaway heat generation model, providing data support for the establishment of battery thermal runway simulation model with composite gas generation characteristics.

Aim at the undersirable situations occurring during the forming process of plastic hot-air riveting, with the purpose of improving the quality of the rivet head, this paper explores the optimal parameter settings of hot air riveting process to improve the quality of rivet head. By changing the heating time, heating temperature and cylinder pressure of the hot air riveting equipment, the orthogonal test of hot air rivet head quality considering the interaction is performed. The multi-index evaluation process of plastic hot air rivet head is established. TOPSIS method is used to sort out the results of multiple evaluation indexes as the response variables of orthogonal test, and the results of orthogonal test are analyzed by range analysis and variance analysis. The results show that the comprehensive score of the quality of the plastic hot air rivet head is the highest, which is 0.835 7 when the heating time of the hot air riveting equipment is 3 s, heating temperature is 190 ℃ and cylinder pressure is 0.7 MPa.

The support base is an important structure for the stable operation of the plasma cutting dust removal device. In order to enhance operation stability this device, this paper makes a structural optimization analysis of the support base based on the ANSYS Workbench software, including sensitivity analysis for design parameter of each structure, and identified 3 factors which have the greatest influence on the stable operation of support base, namely upper wall thickness, support wall thickness and support height. A second-order mathematical response surface model is constructed based on the experimental design methods, and iterative optimization is made through multi-objective genetic algorithm. The simulation results show that the natural frequency of the bearing increases by 20.47% and the maximum stress concentration decreases by 6.57%. The optimal Pareto solution of the parameter variables is achieved within the design requirements and the durability of the beam is significantly improved, which meets the optimization requirements.

In order to study the contribution of intelligent connected automobile manufacturing factories to carbon emission reduction, this paper investigates energy consumption of conventional automobile manufacturing factories and intelligent connected automobile manufacturing factories in terms of construction, process, operation and management, and production process, calculated energy consumption and carbon emission indexes of the conventional factories and the intelligent connected factories and analyzes energy consumption and carbon emission. The study finds that the construction and operation of the intelligent connected automobile manufacturing factories can achieve effective control of total energy consumption and intensity and total carbon emission and intensity, reduce energy consumption and substantially reduce carbon emissions.

With the increasing prevalence of small batch and multi variety production modes in the automotive manufacturing industry, engine companies have developed a large number of modular subpackage scenarios to address the differences in the number of workstations, personnel configuration, and process layout between different engines under this mode, and further enhance the efficiency, flexibility, and scalability of production lines. This paper takes an engine assembly production line as an example to compare the concepts and characteristics of 2 modes, namely, online subpackage and centralized subpackage. The design parameters of the 2 subpackage modes are explained, and a mathematical model of process quota is proposed. MATLAB is utilized to simulate the relationship between process quota and output in the centralized subpackage mode, and the critical conditions for lean management of the 2 subpackage modes are obtained to improve lean control capabilities and provide reference for subpackage planning of related production lines.

To improve the robustness of traditional brake disc surface defeet detection, an automatic detection instrument based on machine vision is designed. The defect features of brake discs are extracted using the Improved Gaussian Difference algorithm and Hough Transform algorithm (IGD-IHT). An identification method for brake disc surface defects is designed based on the Perception-based Image Quality Evaluator and Dempster rule-improved Bayes particle swarm optimization-Nonlinear echo state network to better identify defects. The experimental results show that accuracy of this method is more than 97%, the false alarm rate is less than 1.5%, and the missing alarm rate is less than 1.5%. The method described in this article is superior to traditional methods and improves the accuracy of brake disc surface defect recognition. Factory testing shows that this method can accurately identify almost all defects, and there are relatively few false positives or false negatives, and has high reliability and stability.

To enhance the management level of Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) in China’s automotive industry, this paper studies the production, usage, and management of PFAS such as Perfluorooctane Sulfonate (PFOS), Perfluorooctanoic Acid (PFOA), and Perfluorohexane Sulfonic Acid (PFHxS) in China’s automotive industry. It further analyzes the current challenges faced by the industry, including the lagging PFAS control regulations and the lack of targeted industry standards. Additionally, this paper proposes governance recommendations to promote PFAS management in China.

The auxetic honeycomb structures, due to their unique auxetic effect, have considerable potential for application in the field of energy absorption. To further improve their mechanical performance, this paper proposes a novel bio-inspired hierarchical origami auxetic honeycomb structure, combining bio-inspired hierarchical design and origami structure. Numerical simulations are conducted to systematically investigate the crashworthiness of the structures under axial compression. The results show that, compared with the traditional auxetic honeycomb structure, the energy absorption capacity of the novel bio-inspired hierarchical origami auxetic honeycomb structure is significantly enhanced. Moreover, the introduction of the origami design ensures more uniform deformation during the axial crushing process, and effectively reduces or even eliminates the initial peak force of the structures.

A list of 31 VOCs with risk limits for human health is obtained by sorting out the compounds in the in vehicle/indoor air quality guidelines of 11 countries. M1 type new vehicles are chosen as objects, a quantitative analysis of 104 volatile organic compounds in cabin of vehicle is conducted based on the summa canister gas chromatography-mass spectrometry method. The test results are compared with the list guidelines to screen for risk volatile organic compounds in cabin of vehicle. Except for the 8 items in the international standard, the screening result shows risk volatile organic compounds in the cabin of vehicle include dichloromethane (2.45~706 μg/m³), vinyl acetate (0.91~440 μg/m³), 4-methyl-2-pentanone (0.49~372 μg/m³), naphthalene 0~24.2 μg/m³), butadiene (0.14~4.80 μg/m)³, carbon tetrachloride (0~7.15 μg/m³), trichloroethylene (0~5.01 μg/m³), 1,2-dibromoethane (0~1.59 μg/m³). Suggestions for the subsequent revision of the national standard for vehicle air quality include expanding the management list of VOCs in the indoor air, reevaluating the limit values of 8 substances in the current national standard, and setting 2 limit values for preventive and hazardous concentrations.

In order to compare the lubrication properties of the four pre-lubricants, this paper studies the influence of friction coefficient on the material thinning rate in the bulging process by numerical simulation. The results show that under the same other conditions, the smaller the friction coefficient is, the smaller the sheet thinning rate is, that is to say the better the lubrication effect is in the bulging test, the smaller the forming limit height of the sheet. Based on the numerical simulation results, four kinds of pre-lubricants are used to carry out bulging test to compare the lubrication properties. The results show that lubricating oil A has the best lubrication properties, followed by lubricating oil D and B, and lubricating oil C has the worst lubrication properties. In addition, it is found that lubricating effect of lubricating oil B weakens with the increase of coating amount, whereas that of lubricating oil C and D increases first and then decreases with the increase of coating amount.