In order to research the damage identification of reticulated shell, the damage identification of reticulated shell was taken on though two-step identification method on the basis of the optimal placement of sensors. The measuring points can be determined according to the optimal placement of sensors, which can be analyzed by the wavelet toolbox of MATLAB, in which make the change rate of modal strain energy the damage index. Then the measuring points of second step can be found. The damage placement can be identified from the second step by the change rate of modal strain energy. The result shows that: the two-step method is feasible.

Analysis earthquake response of the long-span tube shell structure under multi-support excitations. The response of the long-span structure in the earthquake is different between multi-support excitations and uniform excitation. Using sap2000 finite element software with time history analysis, this paper analyzes the impact of the different visual velocities combining with the engineering Projects, and its internal forces and displacements. The results show the impact of the long-span tube shell structure under multi-support excitations. Draw structure peaking acceleration and displacement of time-histories. Result shows that: The appearances of structure under multi-support excitations and under uniform excitation have the same trend. The peak of acceleration and displacement of the structural is different from multi-support excitations and uniform excitation, and the time of occurrence of the peak acceleration and peak displacement is also different.

Based on relevant flow rule, Von Mises yield condition and the virtual displacement principle determined by the updated-Lagrange configuration, nonlinear finite-element analysis of the tube-plate connection of K-shape by ANSYS program is studied in this thesis. In order to study the influence of main pipe to the ultimate strength of the tube-plate connection of K-shape, two geometric parameters are considered, D, diameter of the main pipe; T, thickness of the main pipe .Three typical failure modes, gusset yielding, main pipe excessive plastic deformation failure and branch local buckling are also summarized. A comparison was made between formula result and analysis of finite element stimulation to validate the veracity of the existing formula.

The mitral valve annulus shape is complex but vital for normal functioning mitral apparatus. In this paper, mitral valve annulus curves at different time instances were matched with image intensities as similarity metric. The quality of matching is described by a cost function, involving a predominant term qualifying the matching quality---image intensities. To ensure the smoothness of the solution to the minimization problem, regularization term was added to generate combined cost functional. Numerical simulation results verified the effectiveness of our method.

In this paper, a research is carried on to identify damage of reticulated shell structures based on the combination of modal curvature method and wavelets transform method. Take a scaled model of the reticulated shell structure as an example to analyze, the cross section of one member supposed to have a slight damage of stiffness reduction. In order to locate the damage, modal curvatures of the structure are taken as damage indexes to perform continuous wavelet transform. Results of the numerical analysis indicate that the difference of wavelet transform coefficients of modal curvature can be used to locate damage roughly, while the wavelet transform coefficients of modal curvature difference can be used to locate damage more precisely with easier and more reliable data processing. So it is clear that the damage identification based on modal curvature and wavelet transform is quite effective.