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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.

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.

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.

Computer simulation on the dynamic buckling of different forms of initial-defect and different boundary conditions plates under axial impact load was carried out by using ABAQUS /Standard.The strain-time history curve of the symmetric point of upper and lower surface is give,they are coincidence before the buckling and suddenly separate when the buckling occur which is called be bifurcation,and the critical buckling time is also acquired. The results indicate that the influence of different initial-defect locations and amplitudes on the dynamic buckling is very great.

The computer simulation of the dynamic buckling on the cylindrical shell subjected to pulse load was carried out by ABAQUS/Expliect. The value of the rectangle and triangle pulse load is the same and the shape is different, and they are applied on the impact end of the cyclindrical shell. The influence of the load amplitude, the shape of load and the effect of the stress wave on the critical buckling time of cylindrical shell were discussed. The radial displacement curve was obtained which indicates that stress wave propagate along the length of the cylindrical shells, and the curve of strain time history is also acquired which is used to judge bifurcation and give the critical time.

Dynamic buckling of bars under step load was studied by considering the stress wave effect. Straight bars without axial inertia were taken as an example when deformation was small. The buckling solution satisfying the boundary conditions was given by the semi-analytic method. The buckling solution was substituted to the dynamic buckling governing equations. The unified expression of dynamic buckling critical load was obtained by discussing the character of the solution. The dynamic buckling critical load was obtained by calculating the value of when the stress wave propagated to the critical length . The value of dynamic buckling load was 2.5 times the one’s of static buckling load with corresponding equivalent length.

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 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.

With the Drucker-Prager yield criterion, the ANSYS software is used to analyze the long-short-pile composite foundation by using three-dimensional nonlinear finite element method. The influences of load on axial stress and maximal axial stress of head of pile with cushion or not have been investigated by simulating composite foundation through nine long piles and sixteen short piles. The result indicates the cushion can reduce the stress concentration in head of pile effectively with increase of load. This conclusion has a certain value for engineering.

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.

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.

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.

The axial impact buckling of thin metallic cylindrical shells fully filled with water was studied through impact experiments and numerical simulations. Low velocity impact tests were carried out by DHR-9401 drop hammer rig. The experimental results indicate that quite high internal hydrodynamic pressure occurs inside the shell during the impact process. Under the combined action of high internal pressure and axial compression the thin-walled shells buckle plastically and the buckling modes take on regular and axisymmetric wrinkles. Under the joint action of the high internal pressure and the axial compression plastic buckling take place easily on the thin-walled shells and buckling modes take on regular and axisymmetric wrinkles. These results of the tests were used to validate a numerical model. The validated model was used in a parametric study of impacted specimens and these included variations in the shell wall thickness, material strength, length of the specimen and velocity of impact.

The experimental studies on the dynamic buckling of the perfect bars with three kinds of lengths under impulsive axial compression were completed and the boundary condition of clamped-fixed was realized firstly in present studies. The time-history curves of axial strain of bars under different impact velocity were recorded. According to the magnitudes of the axial strain and bifurcate time, the quantitative relation of dynamic buckling load and critical bifurcate length are achieved; according to the curves recorded, the lateral velocity of bars are computed also. The experimental results show that the dynamic buckling load of the bar is distinctly greater than the static one, the front of stress wave can be regarded as fixed and the effect of the axial stress wave in the dynamic buckling of bar must be considered.