Topological Optimiation Lightweight Design For Aluminum Alloy Semi-trailer Key Structures

At the end of the last century, by the problem of energy shortage and environmental degradation become more and more serious, and the awareness of sustainable development, energy conservation, environment protection, the projects of energy and environment issue have been concerned by the world. In the Automotive industry, the reduction of fuel consumption and emissions is closely related to energy and environment.In these years, energy saving has become an important subject in the Automotive research area. The mass of car is important for fuel consumption and emissions, statistics show that 10% decline in the mass can reduce 6%～8% of fuel consumption. So the lightweight of car is very necessary and extremely important not only in view of energy saving but also in the side of emissions. As a heavy cargo of machinery, semi-trailer's lightweight is a great significance in the terms of energy conservation, and has a great impact on the structure performance and economy.Nowadays, there are two commonly ways to lightweight structures:One of it is using lighter and stronger material. There bas begun a large selection of aluminum alloy as the material of automotive parts. The other mean is change the frame of structure, under the premise of meeting requirements of utilization, redistribute structural materials, maximize material utilization, this method is known as structure optimization. With the rapid development of computer technology and maturity of numerical algorithm and finite element theory, a number of soft wares such as Hyperworks, Ansys which based on finite element analysis come out. Based on CAE technology, the optimal design can greatly reduce the designers'workload, and more importantly, it can shorten design cycles, lower manufacturing costs, increase market competition for the product.The material of semi-trailer which is analyzed in this paper is aluminum, and its material layout is the object of study. Optimize the structure of platform floor with Altair HyperWorks Engineering Software, min compliance as objective function, responses of displacement and volume fraction to be the constraint function, size optimization is the further optimization which has to do after the. Compare with the original structure, new structure which is suggested by optimization is 13.7% lighter, and the characters of deformation, stress and vibration are better. Use topology optimization and size optimization to Optimize frame structure, the new structure lighter than the original frame, mass reduces by 60kg, and also the static characteristics of the frame have been greatly improved.The third part optimizes carriage structure by experiment optimum design and topology optimization; by two different methods obtain two different structures, compare the structures, and get the following conclusions:the better structure can be suggested by the methods, but the topology optimization has shorter design cycle, and the experiment optimum design much more complicate than the other, in the actual application, topology optimization is more practical.