In order to study the influence of sound absorption factors on automobile headliner, impedance tube is used to test the sound absorption characteristics of automotive headliner materials based on the transfer function method; the flow resistance of the headliner is tested based on the direct current method, to analyze the effects of production process, fabric, PU, glue and flow resistance on the sound absorption of the headliner. The results show that the production process, fabric layer and PU are the main factors affecting the sound absorption factors on the headliner. The sound absorption coefficient of the two-step production process is increased by 0.1~0.45 in the frequency range above 1 000 Hz; the sound absorption coefficient of knitted fabric is higher than non-woven fabric by 0.05~0.29 in the whole frequency range. Above the 1 000 Hz frequency, when the thickness or density of PU is increased, the sound absorption coefficient is increased by 0.02~0.43, and the peak of sound absorption is close to 1. The average sound absorption coefficient increases with the flow resistance. Reasonable selection of headliner with high flow resistance can effectively increase the resistance of sound wave propagating in the material, which is conducive to rapid attenuation of sound energy and improvement of sound absorption effect.

Microstructured materials are increasingly favored due to their excellent performance. This paper introduces the concepts, principles and configurations of microstructured materials, it lists common types of microstructured materials, including porous metals, porous ceramics, foamed plastics, sandwich materials, etc., analyzes their applications in automotive safety, NVH and thermal management, describes and prospects the development concept of material-structure-function integrated product.

In order to rationally plan workshop layout, this paper proposes an assembly workshop layout planning method based on genetic algorithm. A mathematical model of workshop layout planning is constructed by linear programming, and the model is solved by genetic algorithm, then assembly workshop of an enterprise is taken as example to verify effectiveness of the model. The research findings indicate that the proposed method can effectively address the workshop layout problem resulting from logistics upgrading, which presents a general solution for the workshop layout planning in discrete manufacturing enterprises under similar circumstances.

This paper introduces system composition, basic measurement principle and system control principle of the in-line measurement system used in BBAC body shop flexible production line, and defines the commissioning requirements for system accuracy guarantee to realize the calibration and compensation of dimensional measurement values. The use of the visual management system IQVIS further assists the body shop to quickly and efficiently analyze the dimensional accuracy of the body in white and predict the changing trend. By setting the out-of-tolerance alarm function, the intelligent management and quality control of the three-level tolerance of the body dimension can be realized, which can significantly reduce the impact of defective body on the subsequent processes.

This article proposes a method for calibrating and verifying interlayer parameters related to delamination in Carbon Fiber Reinforced Plastic (CFRP) laminates, as well as establishing a failure model based on *MAT_58. In terms of interlayer parameter calibration, the critical shear strain potential difference under interlayer failure is mainly extracted from the out of plane shear strain and normal strain cloud map of the short beam shear experiment to calculate the interlayer shear strength of composite materials. Furthermore, drop hammer impact experiments are conducted on the materials at 10 J and 200 J energy levels, as well as simulations of laminated shells and refined mesh sizes, to verify the effectiveness and modeling practicality of interlayer parameters. The results showed that the P16M2 model had a threshold load error of 5.09% and a peak force error of 8.99%, proving the effectiveness of interlayer parameters. Furthermore, based on the performance of each model in simulation accuracy and computational cost, increasing the number of layers of laminated shells is more effective than refining mesh sizes.

To address the limitations of the electric drive system in terms of performance, this paper proposes a performance detection method based on key parameters, which introduces machine learning algorithm based on Gradient Boosted Decision Tree (GBDT) to construct and verify the performance quality detection model, including quality sample data collection, feature engineering analysis, model construction, model fusion and model self-training mechanism, etc., to determine product performance inspection quality based on key production and processing parameters of electric drive system. Combined with production practice, the paper proposes the idea of application scenario construction and its deepening direction. The results show that electric drive system quality inspection can be realized based on key parameters.

The sealing of power batteries is of great importance to the safety of battery packs and the vehicle. This paper discusses the common sealing technology of battery pack in the automobile industry at present, and emphatically analyzes the material characteristics and process planning of two-component foaming sealant. The paper also analyzes process flow, ambient temperature, equipment key system, pack sealing check, equipment spot check and maintenance, etc., and summarizes a set of sealant quality control scheme. Effectiveness of this scheme is proved through practical production verification.

This article mainly introduces a fast verification of the effectiveness of the optimization scheme for durability cracking of body sheet metal using a simple bench test combined with Miner principle, and then verifies it through vehicle durability testing to form a close-loop optimization method. First, reproduce the problem of body sheet metal cracking in vehicle enhanced durability testing using CAE analysis method. Then, confirm the cause of body sheet metal durability cracking and make optimization scheme. Next, through CAE simulation analysis, design a simple bench test. Through this simple bench test, it is necessary to accurately reproduce the durability cracking problem of body sheet metal, then quickly verify the effectiveness of the optimization scheme. Finally, after verification through vehicle durability testing, the body sheet metal with added optimization scheme did not show any durability cracking problem, which proves the accuracy and effectiveness of this method.

Based on the physical characteristics of the hollow camshaft, the straightening process and parameters are redesigned and optimized, the straightening downward pressure is re-calculated and optimized, and the straightening fulcrum is expanded to increase the downward pressure to solve the difficulty of rebound. The theoretical basis of hollow camshaft straightening is optimized by fitting the straightening curve, optimizing the weight of correction coefficient and controlling the number of straightening times through a large number of real straightening data. At the same time, the process control is made to the previous process, controlling the straightening quality and waste rate of the hollow camshaft, which achieves lean manufacturing and improve the quality control level of the hollow camshaft production process.

In order to improve the flexibility level of the integrated body casting production line, through the study of the flexibility and full automation of the material rack, gripper, fixture, logistics and assembly unit, the forward products is designed for the purpose of manufacturing needs, which takes into account the needs of the manufacturing process, and satisfies the requirement of reliable performance, strong practicability, and flexible and rapid switching of multiple platforms and models so as to meet the production requirements of high quality, high efficiency, low cost and multi-model.