Abstract: In order to solve the problem of calculating the deflection and stiffness of a two-stage parabolic variable cross-section leaf spring with a sub-spring placed below, taking the 2+1 sub-spring as an example, based on the deformation principle of a simply supported beam in material mechanics, the corresponding deflection of each leaf of the leaf spring is analyzed, and a deformation consistency equation is established. According to the principle of virtual work, an integral equation for end load and deflection is established and solved, and the calculation methods for deflection, stiffness, and end load are summarized. Through experimental verification, it can be seen that the maximum deviation between the calculated value and the experimental value is within 5%, and the calculation theory is correct, which can provide a reference for the forward design of such leaf springs.

Key words: Suspension; Sub-spring placement; Deflection and stiffness; End load

摘要： 为解决副簧下置式二级刚度抛物线变截面少片簧，在副簧接触后的板簧总成挠度和刚 度计算的问题，以 2+1 下置副簧为例，根据材料力学简支梁变形原理，分析板簧各片相应的 挠度情况，建立变形一致方程。根据虚功原理，建立并求解端部载荷和挠度的积分方程，总 结挠度、刚度和端部载荷的计算方法。通过试验验证可知，计算值与试验值最大偏差在 5%以 内，计算理论正确，可以为此类板簧正向设计提供参考。

关键词: 悬架；副簧下置；挠度和刚度；端部载荷