A Generalized Three-Sub-Step Composite Implicit Time Integration Method with Improved Accuracy and Convergence for Linear and Nonlinear Dynamics

In this paper, an improved generalized three-sub-step composite time integration method is proposed for structural dynamic problems. The proposed method has multiple free parameters which can be utilized to optimize the algorithm properties such as calculation accuracy, numerical dissipation. With these free parameters, the new method can harvest controllable numerical dissipation, second-order accuracy, and unconditional stability. Theoretical analysis and numerical simulations demonstrate that the proposed method has far higher accuracy for various linear and nonlinear dynamics than other competitive methods. Especially for conservative nonlinear dynamic systems, the proposed method shows significantly better performance in energy conservation.