基于载荷等效合成与Wigner-Ville变换的汽车耐久性多轴载荷谱加速编辑  

Accelerated Editing for Vehicle Durability Multi-axis Load Spectrum Based on Load Equivalent Synthesis and Wigner-Ville Transform

作　　者：杨永乐 张金保 张志飞[1] 张佑源 林伟雄 YANG Yong-le;ZHANG Jin-bao;ZHANG Zhi-fei;ZHANG You-yuan;LIN Wei-xiong(College of Mechanical and Vehicle Engineering,Chongqing University,Chongqing 400044,China;Dongfeng Liuzhou Motor Co.Ltd.,Liuzhou 545005,Guangxi,China)

机构地区：[1]重庆大学机械与运载工程学院,重庆400044 [2]东风柳州汽车有限公司,广西柳州545005

出　　处：《中国公路学报》2025年第2期296-312,共17页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(51875060)。

摘　　要：汽车耐久性载荷谱加速编辑目的在于提高零部件的疲劳分析效率。针对多轴载荷谱编辑中效率偏低、参照信号损伤特性表征不足等问题,提出一种结合载荷等效合成与Wigner-Ville变换的多参数指标约束编辑方法。基于多轴雨流投影技术对多轴载荷开展以损伤参量最大为基础的等效合成,并作为参照信号进行Wigner-Ville变换获取瞬时能量谱,再结合遗传算法优化双阈值模型确定加速阈值,从而定位无/小损伤时间片段,编辑得到多轴加速谱。以实测轮心六分力载荷谱为示例开展编辑,就预处理过程提出一种修正向下重采样法以消除传统重采样中因峰/谷值漏采造成的损伤加载差异。将所提多轴载荷谱编辑法与基于应变参照信号编辑法进行损伤表征和编辑效果对比;同时,亦将其与时域编辑法、短时傅里叶变换编辑法的编辑效果从多方面进行对比分析。结果表明:相比应变信号,所提方法合成的等效载荷更能有效表征多轴载荷的损伤特性,用作参照信号的编辑效果更优。此外,基于Wigner-Ville变换方法所得瞬时能量谱可用于准确识别原始载荷中无/小损伤数据。压缩效果显示,基于相同伪损伤保留比,所提方法将原始载荷谱压缩至76.50%,且对应均方根和峰度系数等统计参数的相对误差在15%以内。功率谱密度和穿级计数分布显示,所提方法仅在小幅值循环频次上实现有效缩减,未明显改变载荷的幅/频域能量特性,即各项特征指标均优于时域编辑法和短时傅里叶变换编辑法。疲劳仿真结果显示,所提方法在保证较高分析精度的同时,计算效率较原始加载提升约26%,加速效果更显著。该方法可有效提高汽车零部件的疲劳耐久性分析效率。The purpose of accelerated editing of automotive durability load spectra is to improve the efficiency of fatigue analysis.To address the low editing efficiency of the multiaxial load spectrum and insufficient characterization of the damage properties of reference signals,a multi-parameter index-constrained editing method,combining load equivalent synthesis and the Wigner-Ville transform,was proposed.Equivalent synthesis of the multiaxial load based on the maximum damage parameter was performed using the multiaxial rain-flow projection technique.The synthesized load was then used as a reference signal to obtain the instantaneous energy spectrum(IES)using the Wigner-Ville transform,and optimal editing thresholds were determined by optimizing the dual-threshold model using a genetic algorithm.Therefore,time segments with little or no damage can be located to obtain the accelerated multi-axis load spectrum.The measured loads of the wheel-center six-component forces were edited as an example,and a modified down-resampling method was proposed during pre-processing to eliminate the damage discrepancies caused by the omission of peaks/valleys in traditional resampling.The proposed method was compared with a strain reference signal editing method in terms of damage characterization and editing effect.Furthermore,the editing effects of the proposed method were compared with those of time-domain editing and short-time Fourier transform editing methods across various aspects.The results showed that compared with the strain signal,the equivalent load synthesized by the proposed method was more effective in characterizing the damage properties of a multi-axis load,and the editing effect was better when used as a reference signal.Moreover,the IES derived from the Wigner-Ville transform accurately identified instances of no damage or minimal damage within in the original load data.The compression effect revealed that,under the same pseudo-damage retention ratio,the proposed method compresses the original load spectrum to 76.50%.

关 键 词：汽车工程 多轴载荷谱编辑 等效合成理论 Wigner-Ville变换 瞬时能量谱 双阈值模型 

分 类 号：U467[机械工程—车辆工程]