面向典型换挡工况重构的参数化试验载荷模型

为解决非平稳随机循环载荷条件下传动试验台架载荷表达问题,提出一种面向典型换挡工况重构的参数化试验载荷模型. 以装载机典型换挡工况变速器传动轴为研究对象,基于小波变换级数分解的方法将其所受非平稳随机载荷数据分解为非平稳的确定性分量（趋势项）与平稳的随机性分量（随机项）；对具有非平稳随机特性的趋势项采用均方根值加权分段函数拟合实现参数化表达,对具有平稳随机特性的随机项在Parseval定理基础上建立随机谐和函数表达,并将两分量表达函数重构,实现参数化试验载荷模型的表达；用小样本装载机整机试验数据验证了面向典型换挡工况重构的参数化试验载荷模型的有效性、非平稳随机特性和非平稳随机相关性,模型可作为装载机典型换挡工况变速器传动轴台架试验的载荷表达. 研究结果对非平稳随机循环载荷条件下试验台架载荷重构具有工程化价值.

Parameterized test load model for typical shifting condition reconstruction

In order to solve the problem of load expression of transmission test bench under non-stationary random cyclic load conditions, a parameterized test load model for typical shifting condition reconstruction was proposed. Taking the transmission drive shaft of the typical shifting condition of loader as research object, the non-stationary random load data was decomposed into non-stationary deterministic component (trend term) and stationary random component (random term) based on the wavelet transform series decomposition method. The trend items with non-stationary random characteristics were parameterized by piecewise functions fitting with RMS weighting. The random term with stationary random characteristics was based on Parseval theorem to establish the expression of random harmonic function, and the two component expression functions were reconstructed to realize the expression of its parameterized test load model. Through the test data of small sample loader, the validity of the parameterized test load model for typical shifting condition reconstruction and its non-stationary random characteristics and non-stationary random correlation were verified, which can be used as a load expression for the transmission drive shaft bench test of the typical shifting condition of the loader. The modeled method had engineering value for test bench load reconstruction under non-stationary random cyclic loading conditions.