【摘要】 本文中针对汽车变车速行驶时路面不平度在空间域是平稳随机过程的特性,提出求解汽车非平稳随机振动响应统计特性的一种新方法。建立了时间域汽车振动2自由度单轮模型,基于时间域与空间域变量及其导数变换关系,推导了相应的空间域汽车振动模型。采用空间频率傅里叶变换,建立了汽车振动空间频率响应特性和时间域振动响应量的空间频率响应特性。采用路面分类标准表示路面不平度的空间域统计特性,建立了由空间频率响应特性求取非平稳振动响应量统计特性的公式。选取某汽车参数和包含匀加速、匀速和匀减速的典型行驶工况,分析了非平稳振动响应量统计特性的变化规律。结果表明,汽车非平稳振动响应量的统计特性随车速的变化而变化,具有时变特性。更多还原

【Abstract】 According to the characteristics that road roughness is a stationary random process in the spatial domain when a vehicle is running at variable speed,a new method is proposed to solve the statistical characteristics of the non-stationary random vibration response of the vehicle. A two-degree-of-freedom single wheel model of vehicle vibration in time domain is established. Based on the transformation of variables and their derivatives in time domain and space domain,the corresponding vehicle vibration model in space domain is deduced. With the Fourier transform of spatial frequency,the spatial frequency response characteristics of vehicle vibration and the spatial frequency response characteristics of vibration response variables in time domain are established. The road grading standard is used to represent the statistical characteristics of road roughness in space domain,and the formula for calculating the statistical characteristics of non-stationary vibration response variables is established based on the spatial frequency response characteristics. The parameters of a vehicle and typical driving conditions including uniform acceleration,uniform speed and uniform deceleration are selected to analyze the variation law of statistical characteristics of non-stationary vibration response variables. The results show that the statistical characteristics of vehicle non-stationary vibration response change with the change of vehicle speed and have time-varying characteristics.更多还原