This study presents the characterisation of multifractality of road excitation time series under different road conditions for prediction of the durability of a suspension coil spring. Road excitation acceleration signals and strain signals were acquired from the suspension system of a vehicle travelling under different road conditions. Multifractal analysis revealed a higher tendency to multifractality in road excitations with more surface irregularities. With the fatigue lives predicted by different strain-life models (Coffin-Manson, Morrow, and Smith-Watson-Topper), fatigue life prediction linear models based on road multifractality were established. It was found that the Morrow-based linear model gave the most accurate estimation of fatigue life, with the highest R² of 0.8762. In conclusion, the models for the prediction of coil springs’ fatigue life based on road multifractality provide an accurate and faster alternative for durability assessment of coil springs. This can significantly facilitate the design process of coil springs to meet industry requirements.

这项研究提出了不同路面条件下路面激励时间序列的多重分形特征，以预测悬架螺旋弹簧的耐久性。从在不同道路条件下行驶的车辆的悬架系统获取道路激励加速度信号和应变信号。多重分形分析表明，道路激励中具有更多表面不规则性的多重分形趋势更高。利用不同应变寿命模型（Coffin-Manson，Morrow和Smith-Watson-Topper）预测的疲劳寿命，建立了基于道路多重分形性的疲劳寿命预测线性模型。结果发现，基于Morrow的线性模型给出了最准确的疲劳寿命估算值，其中R ²最高为0.8762。总之，基于道路多分形性的螺旋弹簧疲劳寿命预测模型为螺旋弹簧的耐久性评估提供了一种准确，快速的替代方法。这可以大大简化螺旋弹簧的设计过程，以满足行业需求。