Guo Yun Lu

Compressive Buckling of Composite Plates with a Delamination

Compressive buckling of laminate plates with a delamination are simulated using ABAQUS 6.8 software. Effects of sizes, positions, asymmetric and shapes of delamination on the compressive buckling are investigated without the consideration of delamination growth and contact. The results indicate the sizes, positions, asymmetric and shapes of delamination have an important influence on compressive buckling.

Research on the Dynamic Buckling of Composite Laminated Plates with One Edge Fixed and Three Edges Simply-Supported

Taking into account the effects of stress wave and the moment of inertia, the governing equations of composite laminated plate under the axial step load are derived by using Hamilton principle. Based on Variable Separation Method, the analytical expression of the critical dynamic buckling load for symmetry composite laminated plates with one edge fixed and three edges simply-supported can be deduced by considering the characteristics of the buckling solution, and the buckling mode is also acquired. Using MATLAB software, the relationship between the critical load and length can be obtained. The influences of different layer parameters and the order of the mode on the dynamic buckling are discussed.

Analysis of Steel Rope Shock Absorber Amplitude Frequency Characteristics under the Basic Excitation

In this paper, the differential equations of the steel rope shock absorber are established under the basic excitation, using the Fourier series expansion method and the Harmonic balance method, the corresponding frequency response equations are derived, then their numerical solutions is got, and the influence of the mass, damping, stiffness, and hysteretic force on the frequency response characteristic is analyzed under the basic excitation. It can be drawn by analyzing and comparing. Under the basic excitation, with the basic simplified mass increasing, the natural frequency will decrease, while the resonance amplitude will increase. With the steel rope damping, stiffness and the foundation damping increasing, the natural frequency will not change significantly, while the resonance amplitude will decrease. With the foundation stiffness increasing, the natural frequency and the resonance amplitude will increase significantly. The equipment mass and steel rope hysteretic force have no significant effect on the frequency response characteristics.

The Influence of First Order Shear Deformation on Dynamic Buckling of Composite Bar

Taking stress wave propagation into account, the governing equations of composite bar with the clamped-fixed boundary conditions considering FSDT (first order shear deformation theory) are derived on the basis of Reddy’ theory and solved by the variable-separated method. The analytic expression of the critical buckling load is obtained basing on the characteristics of homogeneous linear equations having nonzero-solution. The results of the theoretical study and the numerical calculation indicate that FSDT has influence on dynamic buckling of composite bar, and the critical buckling load is small when FSDT is considered. They also show that the magnitude of effect taken by FSDT is small when the layer angle is big.

Dynamic Buckling of Elastic Cylindrical Shells under Axial Step Load

Considering the effect of stress wave, the dynamic buckling of circular cylindrical shells under an axial step load is discussed using the classical shell theories and the state-space technique in the paper. Based on the Hamilton’s principle, the dynamic buckling governing equations of shells are derived and solved with the Rayleigh-Ritz method. If the linear homogeneous equations have a non-trivial solution, the determinant of the coefficient matrix must be equal to zero, so the expression of the critical load on the dynamic buckling is got. The relationship between the critical load and length is obtained by using MATLAB software. The influences of boundary conditions, thickness, the number of circumferential waves and the number of axial waves on the dynamic buckling loads are discussed based on numerical computation.

Numerical Simulation and Experimental Study on Fluid-Filled Hemispherical Shell under Impact

The dynamic response of fluid-filled hemispherical shell in mass impact is studied by experiment using DHR9401. Combining the time history of impact force with experimental observation of the deformation process, it can be seen that the dynamic response can be divided into four stages: the flattening around the impact point, the forming and expanding outward of shell plastic hinge, the plastic edge region flatten by the punch, and elastic recovery. The experimental results show that: Because the shell filled with liquid, the local impact load that the shell suffered is translated into area load and loads on the inner shell uniformly, so that it has a high carrying capacity. Numerical simulation is used to study the time history of energy absorption of different shell structures. The result shows that the crashworthiness of sandwich fluid-filled shell is improved greatly. Under the certain impact energy, deformation of its inner shell is very small, which can provide effective security space.

Computer Simulation of Cylindrical Shell Penetrated by Rigid Projectile

Computer simulation of cylindrical shell subject to lateral impact by rigid projectile is carried out. The effects of three kinds of typical rigid projectiles, geometric parameters of cylindrical shell and constraint conditions on critical speed are analyzed. The results indicate that the shape of projectile and size of cylindrical shell have a great influence on penetration, and the tapered projectile has a minimum critical speed. The influence of constraint conditions on penetration has a great relationship with thickness of cylindrical shells; energy distribution varies with different thickness of cylindrical shells.

Computer Simulation of Static Buckling of Double-Layer Portal Frame

The buckling of no-way double-layer portal frame that column is fixed is simulated by using ANSYS. Through analyzing the portal frame subjected to different loads on the roof of the structure that are uniform load, trapezoidal load and triangular load, the critical buckling load of the double-layer portal frame and buckling mode are obtained. The regular between the critical buckling load and the form of the load on the roof can be acquired by the analysis of the results, which can be used as a reference for engineering application.

Computer Simulation Research on Dislocation Steel Joints Used in Rebuilding Ancient Tower

For rebuilding an ancient tower at province Gansu, the structure of dislocation steel joints was used make the tower having filtering contraction shape. For this kind of dislocation steel joints structure, there are no relevant calculation regulations in the Code for design of steel structures in China. To investigate the mechanical characteristics of the joints and ensure the safety of the joints and the whole structure under the applied and seismic load, the computer simulation research on the dislocation steel joint was carried out according to the design requirement. Under the extensive analysis the comprehensive understanding of the mechanical characteristics of the dislocation steel joints was obtained and the reference basis for design was provided.

Dynamic Buckling of Composite Bars Subject to Axial Impact

The dynamic buckling of composite bars subject to axial rigid body impact are simulated using the finite-element software ABAQUS6.8. The critical velocity and the bifurcate time are obtained by stain-time curve and effects of fiber angle and impact velocity on dynamic buckling behavior of composite bars are also investigated. The results indicate that the ply angle and impact velocity have an influence on dynamic buckling of composite bars.