Simulation Study On Drop Impact Of Military Product Packages

Military product packages is suffering from drop, shork, vibration and so on inevitably druing circulation process. Drop impact is the main cause of damage, so it is necessary to quest the damage state of military packages caused by drop impact. One of the method of questing the damge state of the transport package is using the product to do the experiment. But the experiment is usually destructive and doing the experiment is expensive; moreover the experiment is uneasily controlled, and physical quantities which are measured are limited. And it is difficult to display the response and vibration deformation mechanism of the structure during the dropping process. One of effective way to solve this problem is using computer software to simulate analysis. To aim at above problems, the article did the dropping simulation analysis about military torpedo's packages.Firstly, the author sums up relatively the basic theory of impact dynamics and comes out with the general analysis way and the process of solving, thus founding the theoretical base for numerical simulation. Then the author combines the basic equation of impact dynamics with Non-linear finite element theory based of MSC.Dytran and establishes the analysis method of drop/impact load.Secondly the torpedo's package was meshed with the software Patran which belongs to MSC company. The finite element model has been finished according to the element types, material model and load. Besides, the author has analyzed and discussed the problems encountered in the modeling.Thirdly based on the non-linear software MSC.Dytran, the drop impact of the torpedo's package has been simulated and analyzed, we can get the impact of the the torpedo and process box impact, stress and energy over time to respond to the situation; the author intensive analyzed the movement and potential failure type of the torpedo, and found out the weakness in structure designing and further helped improve or optimize designing after synthesizing these analysis results; Analysis also can be drawn through the torpedo of packages to meet the national requirements of the impact resistance requirements.Finally, the influence of drop impact parameters (velocity, position) is analyzed. From the study, we find that the torpedo force is affected by drop parameters. We can change the drop parameters to improve the situation of torpedo force.