包装动力学响应中避免缓冲材料厚度无极限的方法

A Method to Avoid the Infinity of Cushion Material during the Process to Solve Dynamic Response of Packaging System

在求解包装动力学响应时,缓冲材料的本构关系常简化为立方非线性、双曲正切非线性等理想的情况。由于未考虑缓冲材料厚度的有限性,不能保证所得结果可靠性。基于缓冲材料在压缩到极限位置时,缓冲材料应力接近无限大,运用正切函数表达了缓冲材料这一限制性特性。数值计算结果表明,若未考虑限制时,动力学响应会超出缓冲材料的极限位置,甚至超过厚度,且得不到优化的包装结构;考虑限制条件,就不会出现上述错误,避免了缓冲材料厚度无极限。

The constitutive relation of cushion material is often simplified to be ideal cubic nonlinear and hyperbolic nonlinear in solving packaging dynamics. Due to the finiteness of cushion material is neglected, the exact response is difficult to obtain. The stress of cushion material can reach infinity when the cushion material being compressed to be extreme position, so it avoid the infiniteness of cushion material by using tangent function to express the special me- chanical phenomenon. The numerical examples show the response of packaging system can exceed the extreme position even the thickness of the material if not considering the constrained conditions, and the optimized packaging structure can not be available ; the error results are disappeared when tangent function is involved to modify the constitutive rela- tionships.