Research On Simulation Model And Method Of Packaging Dynamics Based On MapleSim

Following various sorts cushion materials are used in packaging field, the cushioning performance of transportation package becomes better. However, it is an issue that how to choose appropriate cushion material for many manufacturers or researchers. Therefore, the testing of transportation package must be performed to verify the cushioning performance before formal production. There are two testing methods---traditional laboratory testing method and packaging CAE(Computer Aided Engineering) method. The former is a main testing method due to high test precision and reliable data. Nevertheless, there are disadvantages such as high probability to damage product, low efficiency and high testing costs for the traditional physical testing methods. On the other hand, the packaging CAE method that was developed following the computer science has repeatability and low cost as its advantages. Nonetheless, it is difficult to promote as a popular method because the condition setup of CAE software is complex and the simulation result is not accurate. Thus, both the traditional laboratory test method and packaging CAE simulation method have advantages and disadvantages. How to combine the two methods effectively is a very meaning researching theme. Therefore, the target of this paper is to research the better testing method for the cushion performance. Based on the previous studies, this paper introduces a new MapleSim simulation method that is based on a mathematic-symbol algorithm firstly. Then, by using theoretical analysis, laboratory test and digital simulation as the research methods, we try to reveal the nonlinear characteristics of the packaging material more accurately on depth and expand the package cushioning properties of the hybrid test method on breadth.Firstly, this paper sorts and summarizes the dynamic cushioning theory, and then proposes the response of the cushion materials to the shock under linear and nonlinear character, respectively. Based on traditional equivalent drop theory, the paper proposes damping equivalent drop theory, which laid a foundation for carrying out the nonlinear characteristics simulation of common cushion material EPE in MapleSim.Secondly, starting from the free fall model, this paper selects mass and spring components to build a model based on a free fall theory. The law of conservation of energy is applied to prove the simulation result. The dynamic compression and shock tests are carried out by using EPE as the testing material. Based on the equivalent drop theory and experimental data, a damping ratio is calculated by matching the experimental results and thus the parameters of components in simulation model are known. The results show that the simulation method based on MapleSim has enough precision for transport package testing.Based on the simulation of the shock test, a controlled equation is defined and a key custom component is built. Finally, this paper realizes more complicated simulation. This paper first simulates package materials without damping and then determines the constant of spring by changing the input signal. In the previous study, the simulation needs to calculate two experiential data. Therefore, more efficient simulation method based on the stress-strain curve is proposed in this chapter. Firstly, we obtain the stress-strain curve of EPE by shock test. Secondly we shift into related parameters of the controlled equation of the custom component in MapleSim. Finally, we realize the cushion performance of EPE to establish a more practical cushion materials simulation method based on MapleSim.The research results show that the hybrid testing method of laboratory testing method and packaging CAE method can improve measurement accuracy, and the cushion materials simulation method based on MapleSim also provide a new way for cushioning performance test of transportation package.