A new method for combination of nonlinear load effects of structures is suggested in the paper. At first, the concepts of load combination and load effect combination are discussed, respectively. A load combination method based on probability space partition is introduced, through which the load effects of structures could be accurately estimated. Afterwards, the principle of nonlinear load effect combination of structures under multiple loads is presented. In order to reflect the nonlinear performances of structures, the physical equations of solid mechanics with a reasonable elastoplastic damage constitutive model are applied to derive structural deterministic nonlinear responses. The probability density evolution equation (PDEE) is used to acquire the stochastic response characteristics of structures under multiple random loads. Hence, the combination of nonlinear load effects of structures is well realized. Furthermore, the reliability of structures under multiple loads is evaluated by using the physical synthesis method. Finally, in order to illustrate the proposed method, the nonlinear load effect combination analyses for a reinforced concrete (RC) plane frame under gravity load and earthquake and a concrete bridge under long-term vehicular loads and earthquakes are carried out. The analysis results demonstrate the applicability and superiority of the proposed method.

提出了一种新的组合结构非线性荷载作用的方法。首先，分别讨论了荷载组合和荷载作用组合的概念。介绍了一种基于概率空间划分的荷载组合方法，可以准确地估计结构的荷载效果。然后，提出了多种荷载作用下结构的非线性荷载作用组合原理。为了反映结构的非线性性能，采用具有合理弹塑性损伤本构模型的固体力学物理方程式来推导结构确定性非线性响应。概率密度演化方程（PDEE）用于获取结构在多个随机载荷下的随机响应特性。因此，很好地实现了结构的非线性荷载作用的组合。此外，通过物理合成方法评估了多种载荷下结构的可靠性。最后，为了说明所提出的方法，对钢筋混凝土平面框架在重力荷载和地震作用下以及长期桥梁和地震作用下的混凝土桥梁进行了非线性荷载作用组合分析。分析结果证明了该方法的适用性和优越性。进行了钢筋混凝土平面框架在重力荷载和地震作用下以及混凝土桥梁在长期车辆荷载和地震作用下的非线性荷载作用组合分析。分析结果证明了该方法的适用性和优越性。进行了钢筋混凝土平面框架在重力荷载和地震作用下以及混凝土桥梁在长期车辆荷载和地震作用下的非线性荷载作用组合分析。分析结果证明了该方法的适用性和优越性。