Analysis And Improvement Of Commercial Vehicle Cab's Frontal Crash Safety

Commercial vehicle has been playing an important role in our transportation and it undertakes a lot of the road transport work. Compared with the passenger car, commercial vehicle has a larger body size and greater weight, its weight will be severely increased when it is laden. So the vehicle will bear a massive amount of impact energy when it encounters a collision accident ev en when it is in a low speed. Now most of the commercial vehicle has a cab-over-engine design, it means the cabin doesn't have enough deformation zone to absorb the impact energy, once it encounters a collision accident, the cabin body will suffer serious deformation and the passenger will be in danger. To protect the passenger and meet the market demand for security of commercial vehicle, research on the impact safety of commercial vehicle is significant.Traditionally we can improve commercial vehicle cra sh safety through optimizing the geometry of car body parts, applying new materials and making the body structure layout more reasonable. Recently the manufacturer improves the commercial vehicle crash safety mainly by means of adding energy absorber, incr easing the thickness of the part which is crucial to frontal impact safety and adding reinforcing plate. These measures improve the cabin's crashworthiness to some extent but also increase the manufacturing cost and body weight at the same time.Taking a commercial vehicle for example, an optimization method based on the application of high strength steel was proposed to improve the cabin's frontal crash safety, considering the manufacturing cost and body light-weight design. Firstly, five components which were crucial to frontal impact safety were selected through global sensitivity analysis. Then, the multi-objective optimization model concerning mass and cost was established after reselecting material type for these components and utilizing high strength steel for the design. Finally, by employing quadratic response surface approximation models and NSGA-? algorithm, the Pareto optimal solution set was achieved. The results show that the weight of the five components is reduced and the cost is also diminished, while the frontal impact safety is improved at the same time. The method proposed in this paper provides a reference to the crash safety design of commercial vehicle.Uncertain factors is ignored in deterministic optimization design, which leads to the optimal solution appears on the constraint boundary. Combining with the contents of this paper, undertaking a reliability-based design optimization on collision safety of commercial vehicle cabin, while considering the uncertainty of sheet thickness. Optimization results show that the passenger's space meets the requirements when considering uncertain factors and the obtained optimization does not appear in the constraint boundary and optimization of reliability higher.