为提高船撞荷载作用下桥梁响应的计算精度, 本文提出了基于梯形简化荷载的桥梁响应计算方法。首先, 本文推导了桥梁的动力学方程; 接着, 基于桥梁运动方程, 进一步推导出了桥梁的状态方程; 然后, 将船撞荷载简化为矩形和梯形形状, 并推导了桥梁状态方程的求解公式; 最后, 通过建立四跨桥梁的有限元模型, 计算了船撞荷载作用下桥梁的响应。结果表明, 当采样频率为100Hz时, 梯形荷载简化方法的计算结果与理论结果基本一致, 验证了所提方法的准确性与高效性。

To improve the accuracy of predicting bridge responses under ship-impact loads, this study proposes a response calculation method based on a simplified trapezoidal load model. Firstly, the equations of motion for the bridge are derived. Based on these equations, the state-space representation of the bridge system is further derived. Subsequently, the ship-impact load is simplified into rectangular and trapezoidal load forms, and the solution formulas of the state-space equations under these simplified loads are obtained. Finally, a finite element model of a four-span bridge is constructed to compute structural responses induced by ship-impact loads. Numerical results indicate that when the sampling frequency is 100Hz, the trapezoidal load simplification method yields response predictions that closely match the theoretical solutions, thereby demonstrating the accuracy and computational efficiency of the proposed method.