基于“双法多程式”的悬架橡胶衬套力学性能估算与试验验证

Test verification and mechanical property estimation for rubber bushing of suspension based on "double methods-multiple equations"

为估算验证橡胶衬套的力学性能,以促进衬套对车辆性能影响研究工作的有效开展,将轿车麦弗逊悬架的衬套作为研究对象,先推导相关应变能密度函数方程,再采用Yeoh,Van der Waals,Ogden(N=3)方程为主的多种本构模型,对衬套NR55橡胶进行材料力学性能估算并与其基础试验结果作对比验证,确定Ogden(N=3)方程为衬套结构力学性能估算的较优本构模型.设定多材料系数μ1,μ2,μ3,α1,α2,α3为优化变量并赋初值,初步估算衬套结构力学性能并分析与结构试验结果的一致性,优化目标是"面积重合"和"位移相等"的四类函数,选择自适应响应面法,经过10次迭代,识别出一组能较好估算衬套结构力学性能的本构模型方程系数值.利用最后一次估算值,求解拟合出新曲线,与基础试验估算拟合曲线、结构试验本身刚度曲线进行比较后发现,径(轴)向的刚度值误差均在9.1%以内,考虑各种因素,工程上属可接受范围,说明所述方法可行,能被推广.

In order to promote some research works of rubber bushing＆#39;s impact on vehicle perform-ances effectively by estimating and verifying the mechanical properties of rubber bushings ,the bushing of McPherson suspension was researched .Firstly ,the relative strain energy density function equations were derived ,and after the introduction of many constitutive model equations （Wherein ,Yeoh ,Van der Waals ,and Ogden as the principal ） ,the material mechanical properties of bushing rubber （NR55） were estimated and then verified by contrasting with the results of ma-terial basic tests ,then 3rd order Ogden equation was determined as a better constitutive model to estimate the bushing structural mechanical properties .The multi-parameters of μ1 ,μ2 ,μ3 ,α1 ,α2 ,α3 were set as variables to be optimized and their initial values were given ,then pre-estimation of the bushing structural mechanical properties was done and verified by contrasting with the results of bushing structural tests ,4 types of optimize objective functions were designated to make’area overlap’ and ’displacement equivalent’,10 interactive processes were performed by selecting adaptive response surface method ,and a set of values of the multi-parameters ,w hich can more accurately estimate the bushing structural mechanical properties ,were identified .Two new curves can be calculated and fitted by using the set of identified values .They were compared with the curves of the structural tests itself and the estimated fitting of material basic tests .The results show that the errors of radial （axial） stiffness values are all less than 9.1% ,if the other various factors are considered ,this can be accepted in engineering .It show s that the above methods are feasible and can be generalized .