车辆制动载荷下包装件非线性摇摆响应分析

Research on freestanding package nonlinear rocking response under vehicle braking condition

车辆制动产生纵向半正弦冲击载荷,浮放包装件在运输过程中制动条件下的摇摆特性及倾覆风险研究对于确保运输安全至关重要。研究浮放包装件非线性摇摆响应(α>15°),构建循环神经网络模拟包装件非线性受迫摇摆响应,应用雅可比椭圆函数构建包装件非线性自由响应分析表达式,根据能量守恒原则构建包装件在自由响应阶段倾覆边界条件。根据包装件非线性摇摆响应分析方法,构建包装件倾覆边界条件。分析结果表明,在半正弦冲击激励下,包装件在受迫响应阶段和自由响应阶段均可能绕O点逆时针旋转倾覆,导致包装件自由响应倾覆的冲击幅值较导致包装件受迫响应倾覆的冲击幅值小,这表明,包装件更容易在自由响应阶段倾覆。

The freestanding package,excited by the half-sine pulse under the vehicle braking condition,sometimes easily overturns during the rocking motion.Therefore,the research on package rocking properties and overturning risks is important for cargo transportation safety.In this paper,nonlinear rocking response of freestanding package is analyzed(α>15°).A recurrent neural network is formulated and trained to simulate forced rocking response of freestanding package with accuracy.Given the initial response angle and angular velocity,in free rocking phase,the Jacobi elliptic functions are used to formulate analytical response expression,the energy conservation principle is applied,the package nonlinear rocking overturning condition is formulated in package free rocking phase.The package nonlinear forced and free response analysis methods are applied to obtain package overturning boundary condition,the simulation results indicate,in both forced and free response phase,the package make anticlockwise rotation about point O and may overturn.The altitude of pulse which can lead to package overturn in forced response phase is greater than that in free response phase,we can conclude the package rocking overturning is more inclined to occurs in free response phase.