New finite strain elastoplastic \(J_2\)-flow equations with no reference to the yield condition are proposed for the purpose of simultaneously simulating low-to-ultrahigh cycle failure effects of metals. As inherent response features of such new equations, the entire responses up to eventual failure under cyclic and non-cyclic loadings of constant and variable amplitudes are automatically predicted, in a direct sense without involving any additional damage-like variables and any ad hoc failure criteria. The thermodynamic consistency is ensured by demonstrating that the intrinsic dissipation is identically non-negative. Furthermore, a high-efficiency algorithm for integrating the elastoplastic rate equations is established toward bypassing very time-consuming numerical procedures in treating cyclic responses with high and even ultrahigh cycle number. With numerical examples, model predictions are shown to be in good agreement with fatigue failure data for low, high and very high cycle numbers, and the new algorithm is shown to be much faster and far more efficient than usual integration procedures.

新的有限应变弹塑性\（J_2 \）为了同时模拟金属的低到超高循环破坏效应，提出了不考虑屈服条件的流动方程。作为此类新方程式的固有响应特征，在恒定的和可变的振幅的循环和非循环载荷下，直至最终失效的整个响应都将自动进行直接预测，而无需涉及任何其他类似损伤的变量和任何临时失效准则。通过证明固有耗散是相同的非负的来确保热力学一致性。此外，建立了一种用于集成弹塑性速率方程的高效算法，以绕过非常耗时的数值程序来处理具有高甚至超高循环数的循环响应。借助数字示例，