The selected high-span continuous rigid frame bridge for studying is Mangjiedu Bridge in this paper. Based on the principle of structure dynamics and the method of seismic response analysis, the finite element model of the main bridge in Mangjiedu Bridge under Midas-civil was built according to the structural features, site conditions and seismic fortification intensity of the bridge. Then the characteristics of main bridge structure were studied using Lanzcos modal analysis method, and the seismic responses of main bridge are studied by earthquake response spectrum analysis and time history analysis respectively. The results show that the fundamental frequency of the main bridge is 0.1943Hz, and the transverse vibration mode shapes are most remarkable in the former 10 ordered types of vibration of main bridge. The main bridge is in the conditions of elastic range and does not failure under E1 earthquake. Both response spectrum analysis and time history analysis show that the largest displacement along the main bridge appears at the top of pier and the largest transverse displacement appears in the central position of main span. It also shows that the maximum shear and maximum moment occur at the bottom of main pier.

Based on the experimental measured cooling curves and the boiling heat transfer theory, the inverse problem of nonlinear heat conduct equation for Steel 1045 quenched by different hardening media was established by functional analysis and finite element method, and the surface heat-transfer coefficients in continuous cooling during quenching were calculated by nonlinear estimate method. Then the constitutive model of Steel 1045 during quenching was established subsequently. Finally, the temperature field of Steel 1045 cylinder quenched by different hardening media was simulated by Finite Element Methods (FEM). Results show that the calculated temperature fields agree with the practical quenching process.

On the basis of plastic-elastic mechanics and finite element method, one selected 150m high reinforced concrete chimney was taken as the target in this paper to analyze the mechanical condition of directional demolition blasting, the capsizing time, the internal force of support abutment and constitutive relation of the chimney during directional blasting. A finite element model of the towering reinforced concrete chimney was established through separated modeling method by finite element analysis software LS-DYNA of ANSYS. Results show that the constitutive relation given by this paper conforms to reality. The finite element model of the towering reinforced concrete chimney established by separated modeling method is reasonable. The real overturn process, capsizing location and capsizing length of towering reinforced concrete chimney during directional demolition blasting are agree with that of numerical simulation.