纵梁的平均压溃力决定着轿车纵梁在碰撞过程中吸收能量的能力．研究纵梁的平均压溃力，可在概念设计阶段了解纵梁的碰撞性能，减少潜在的设计缺陷．但文献中纵梁平均压溃力的拟合结果与试验及仿真偏差较大．为此，文中采用物理试验与仿真试验相结合的方法，分析平均压溃力与材料的截面形状、厚度和力学性能的关系，并对一系列单元薄壁矩形截面梁进行试验与仿真，根据统计学中极差、最大偏差和标准差最小化原则，推导出新的矩形截面梁平均压溃力公式．计算结果表明，所推导公式的拟合值比现有文献公式的更加接近仿真值，能够满足轿车前纵梁概念的设计需要．

The energy absorption ability of a car rail during crash depends on the mean crush force of the rail.Themean crush force research helps to know the rail impact performance and reduce the potential defect at conceptdesign stage.However,as for the mean crush force,there is a considerable discrepancy among tests,simulationsand fitting results in literatures.In order to solve this problem,this paper analyzes the relationships between themean crush force and such parameters as the beam shape,beam thickness and mechanical properties of material bycombining physical tests with simulations.Then,a series of single- cell thin- walled rectangle section beams areemployed to carry out tests and simulations,and a new formula of mean crush force is deduced for the beams on thebasis of minimization principle of range,maximum deviation and standard deviation.The calculation results showthat the deduced formula achieves a fitting value which is closer to the simulation value than that in literatures,andit can meet the concept design requirement of frontal rail.