We present the underlying dynamics of snap-through structures that exhibit twinkling. Twinkling occurs when the nonlinear structure is loaded slowly and the masses snap-through, converting the low frequency input to high frequency oscillations. We have studied a nonlinear spring-mass chain loaded by a quasistatic pull. The spring forces are assumed to be cubic with intervals of negative stiffne...

The accurate prediction of the spring back has great significance to the cold bending of plates. Based on the analysis of the square non pressure head CNC bending machine forming principle, the finite element model of the cold forming of the hull plate surface was established using the ANSYS/LS-DYNA finite element software. And the spring back computing research was done on the thickness of 8 m...

The purpose of optimizing isolator parameters is to have a system that is stiff at low frequency but soft in high frequency. However, in this case a small amount of transmitted force will cause a large displacement in isolator. Exceeding the allowable relative displacement may cause serious damage to the system. Therefore a trade off between the transmitted force, which is indicated by absolute...

the nonlocal nonlinear buckling of a double layer graphene sheet (dlgs) covered by zinc oxide (zno) piezoelectric layers is investigated in this study. the surrounding circumstances of the system are considered as a pasternak foundation including spring constants and a shear layer. graphene sheets are subjected to longitudinal magnetic field and biaxial forces. on the other hand, the zno piezoe...

Detection of incipient (slowly developing) faults is crucial in automated maintenance problems where early detection of worn equipment is required. In this paper, a general framework for model-based fault detection and diagnosis of a class of incipient faults is developed. The changes in the system dynamics due to the fault are modeled as nonlinear functions of the state and input variables, wh...