Finite Difference Method And Computer Simulation Of Dynamic Buckling Of Bar

As one of the most commonly used basic components in the engineering, the bars have been applied in the field of construction machinery, aerospace, automotive infrastructure, etc. So the dynamic buckling of bars have always been favored by researchers, but the research results are not the same because of the different materials, methods, angles and so on. In this paper, the finite difference method and computer simulation are used to further study the dynamic buckling of bars:1. The research history and current situation of the dynamic buckling of bars are briefly introduced in the domestic and in abroad, and the principle and properties of the finite difference method are introduced.2. Using the first order shear theory and considering the stress wave effect, the dynamic buckling control equation of the elastic bar with initial imperfections, transverse inertia and axial inertia is derived according to the Hamilton principle.3. Considering the axial inertia and transverse inertia, the finite difference method is used to solve the dynamic buckling control equations. The buckling modal, buckling critical load and critical time are obtained. Numerical results show that the influence of stress wave propagation on the buckling behavior is huge. Dynamic buckling is related to critical time and axial impact velocity, the longer critical time and the higher axial impact velocity, the high order mode is more likely to be excited and the maximum value of wave crest and trough also increases. When the impact speed reaches to a value, half wavelength tends to be stable. The impact end of fixed support is better resistance to the buckling than simply supported. The results of the finite difference method are in agreement with the results of the analytical solution.4. Using the first order shear theory and considering the stress wave effect, the governing equations of dynamic buckling of composite bars are derived according to the Hamilton principle. Considering the axial inertia and transverse inertia, the finite difference method is used to solve the equation. The results show that the influence of stress wave propagation on the buckling behavior is huge, and the results of the finite difference method are in agreement with the results of the analytical solution. As the increase of ply angle, the tensile stiffness decreases, wave crest and trough maximum value increases, maximum half wavelength decreases, stress wave velocity decreases.5. The dynamic buckling of elastic bar with two different boundary conditions under step load and impulsive load is simulated by ABAQUS. The influences of impact load, stress wave propagation and constraint condition on dynamic buckling are discussed, and the simulation results agree well with the theoretical results.6. The dynamic buckling of elastic bar with different initial imperfections under step load is simulated by ABAQUS, and the effect of initial imperfection and stress wave propagation on the dynamic buckling of elastic bar is analyzed.