In this study, the silicone-oil damper of a heavy-duty diesel engine is taken as the research object, and a linear cumulative damage model of the silicone-oil damper is developed by taking silicone-oil deterioration as a damage parameter. Based on the results of mixed cycle and load cycle durability engine bench tests, the life model of the damper is calibrated. Combined with the measured road load spectrum, the service life of the silicone-oil damper in actual usage scenarios has been predicted. The results show that under the working condition of the tractor, the predicted life of the M60 damper based on mixed cycle and load cycle tests is 1.425 million km and 2.896 million km, respectively, both of which meet the requirements for engine life mileage.

In order to analyze the influence of the adhesive layer on the surface quality during the manufacturing process of the sandwich structure, modeling and analysis are carried out in the finite element analysis software ABAQUS with PMMA as the main research object. During the hot-pressing manufacturing process of the sandwich structure, the influence of the adhesive on the surface quality is studied through the 2 processes of heating and pressurization. The results show that when only the heating process is considered, due to the viscoelasticity of the adhesive, PMMA will become softer as the temperature rises, which will lead to an increase in the surface waviness; when only the pressurization process is considered, the viscoelasticity has almost no effect on the surface waviness. When the hot-pressing is coupled, the surface waviness will be greater than that when only heating or pressurization is considered alone; the softer the adhesive, the greater the surface waviness. By adjusting the characteristics of the adhesive, the surface quality of the sandwich structure can be effectively controlled, thereby improving the overall quality of the product.

To explore the application value of topological optimization design method based on additive manufacturing in the field of commercial vehicle lightweighting, this paper proposes 2 types of optimization schemes through the optimization process of topological calculation, geometric reconstruction and print simulation analysis taking the commercial vehicle post processor bracket as the test object, and the Selective Laser Melting (SLM) process is utilized to complete the physical additive manufacturing. Finally, both schemes pass the verification of the 8 000 km enhanced road bench test, the results indicate that the topology optimization design method based on additive manufacturing fulfills the design and performance requirements.

To obtain high-performance heat-treated free aluminum alloys, 3 kinds of Al-Si based heat-treated free aluminum alloys with different composition ratios are designed by adjusting the mass fractions of each element in the alloy. The melting temperature range, structure phase composition, fracture morphology, tensile and fatigue performance of 3 kind of alloys are analyzed by using Differential Scanning Calorimeter (DSC), metallographic microscope, scanning electron microscope, tensile testing machine and electromagnetic resonance fatigue testing machine. The results show that 2# alloy has good casting fluidity, metallographic structure, comprehensive strength and toughness properties and casting manufacturability, with a melting temperature range of 55 ℃, the tensile strength, yield strength and elongation rate at break are 303 MPa, 153 MPa and 11.3%, respectively. The average axial tensile compressive fatigue strength at 1×10⁷ cycles is 125 MPa, which is superior to the fatigue performance of AlSi9Cu3 (Fe) die-casting alloy commonly applied in the automotive industry.

In this study, taking the sealing structure of oil pump flanges as the research object, a rough peak contact model and a parallel flat plate leakage model are further established to calculate the leakage rate of the sealing surface based on the contact pressure distribution on the sealing surface obbtained by finite element mechanical analysis. At the same time, the time-temperature equivalent model of rubber performance is established by rubber accelerated aging test so as to predict rubber sealing life. Finally, the rubber sealing life is verified by seal leakage rate bench test, proving that the test result is basically consistent with the prediction result.

In order to rapidly select the best lubricating grease for vehicles in different conditions, 4 actual vehicle working conditions are simulated including normal driving, heavy load, climbing and high speed using a four-ball machine with the wear diameter of the measured sample as evaluation index. Combined with droplet point, evaporation loss and oxidation stability, the performance of 4 long-life composite lithium based grease is studied, and the best choice of lubricating grease under different using scenarios are summarized as well.

Cooling performance of coolants with 6 different types and contents of additives is studied through cooling rate experiments. The result shows that the cooling performance of the coolants with the nonionic additive is the best, followed by the coolants with the mixed additive, and the coolants with the ionic additive exhibits the worst cooling performance. The lower the additive content, the better the cooling performance of the coolant. The cooling performance of coolant A containing 0.11% non-ionic addifive by mass is the best, with the shortest time corresponding to the probe temperature reaching 200 ℃, which is 6.1 s and the maximum cooling rate reaches 60 ℃/s.

At present, 6016 aluminum alloy automotive sheet has attracted much attention for its excellent performance. This paper discusses the whole process production technology of 6016 aluminum alloy automobile sheet, including chemical composition, melting and casting, rolling, heat treatment, chemical treatment and electrostatic oiling, and emphatically expounds the basic principle, technical status and research progress of each production process. It finally prospects the development directions of 6016 aluminum alloy automobile sheet production technology in aspects of chemical composition design, new melting and casting technology, short process rolling technology, heat treatment technology, chemical treatment technology and key equipment localization.

To explore the application of micro foaming blow molding technology in automotive air ducts,this paper adjusts the blowing presstre and temperature in the production process to obtain qualified samples and rerifies their material properities and product performance. The results show that, compared with the unfoamed air duct, air duct parts with foaming ratio of 10% experience significant degrease of tensile and bending performance, with performance degradation up to 40%. In the foaming ratio range between 10% to 30%, with the increase of foaming ratio, the tensile and bending performance of the air duct material gradually decrease, but compared with tensile strength, the bending strength decreases more slowly. The air duct with foaming ratio of 30% not only meets the appearance requirements, but also meets the product performance requirements for automotive products. At the same time, by trial production of air ducts with different structures, the design points of microfoaming air duct are summarized.

This paper analyzes and summarizes the impact of China’s natural environment, industrial atmospheric environment and road conditions on the occurrence and acceleration of corrosion in automotive metal materials. The results show that temperature, relative humidity, soil acidity and alkalinity, salt spray in coastal areas, road deicing salt, and industrial atmospheric pollutants are key factors that induce and accelerate the corrosion of vehicle bodies and components. Therefore, in automotive development, rational anti-corrosion design should be made based on these key factors, and corresponding corrosion verification methods should be established to improve the compatibility between the anti-corrosion performance of vehicles and their actual corrosion life, thereby reducing quality issues and cost waste telated to anti-corrosion.

For the instrument panel beams made mainly of steel, aluminum-magnesium alloy, and composite material, this paper compares the instrument board beams of different processes in terms of lightweight, accuracy, and cost, studies and analyzes the use scenarios and application trends of instrument panel board, and compares the technical defects and process restrictions of different types of instrument panel beams. The study believes that with the general use of composite material beams, the cost advantage of steel beams and the lightweight advantages of aluminum-magnesium alloy beams will no longer be significant, while composite material beams will become the mainstream trend of process manufacturing.