Taking the bending stiffness, static sag, and geometric non-linearity into consideration, the space nonlinear vibration partial differential equations were derived. The partical differential equations were discretized...Taking the bending stiffness, static sag, and geometric non-linearity into consideration, the space nonlinear vibration partial differential equations were derived. The partical differential equations were discretized in space by finite center difference approximation, then the nonlinear ordinal differential equations were obtained. A hybrid method involving the combination of the Newmark method and the pseudo-force strategy was proposed to analyze the nonlinear transient response of the inclined cable-dampers system subjected to arbitrary dynamic loading. As an example, two typical stay cables were calculated by the present method. The results reveal both the validity and the deficiency of the viscoelasticity damper for vibration control of stay cables. The efficiency and accuracy of the proposed method is also verified by comparing the results with those obtained by using Runge-Kutta direct integration technique. A new time history analysis method is provided for the research on the stay cable vibration control.展开更多
As the bridge engineering community sets sails to use longer and longer spans, more and more sophisticated analysis models have to be used in the design process. One of the significant problems represents cable ruptur...As the bridge engineering community sets sails to use longer and longer spans, more and more sophisticated analysis models have to be used in the design process. One of the significant problems represents cable rupture of cable stays. The problem is also addressed in guidelines for cable-stayed bridge design such as PTI （Post-tensioning Institute） Recommendations and EC3 by quasi-static analyses using DAF （dynamic amplification factors） to account dynamic effects, which can be conducted instead ofnsing dynamic analysis. The results show that the value DAF depends on the cable rupture location and on the type and location of the examined state. Dynamic time history analysis is recommended. Some projects examples are highlighted in the paper, where the importance of above mentioned topic has been investigated, following different regulations and approaches. Professional bridge analysis and design sottware solution RM Bridge has been used for all investigations. The application can fulfill all requirements and deliver expected and accurate results. In addition, RM Bridge Sottware also helps engineers as a tool to optimize structure design and increase resistance capacity for each element to ensure the structural safety in service stage.展开更多
The problem of geometric non-linearity simulation for spacial cable system was solved by introducing the truss element based on corotational coordinate (CR) system, cable structure materials and node coordinates and a...The problem of geometric non-linearity simulation for spacial cable system was solved by introducing the truss element based on corotational coordinate (CR) system, cable structure materials and node coordinates and automatic refreshing algorithms for element internal force. And the shape-finding problem for maneuvering profile was solved with the Newton-Raphson based on energy convergence criteria with search function. This has avoided the regular truss element assumption extensively used in traditional methods and catenary elements which have difficulties in practical application because of the complicated formulas. The use of CR formulation has taken into account the stiffness outside the cable plane via a geometric stiffness matrix, realizing the 3D space analysis of a cable bridge and improving the efficiency and precision for the space geometric non-linearity analysis and cable structure, and enabling more precised simulation of geometric form finding and internal force of the large span suspension bridge main cable under construction.展开更多
文摘Taking the bending stiffness, static sag, and geometric non-linearity into consideration, the space nonlinear vibration partial differential equations were derived. The partical differential equations were discretized in space by finite center difference approximation, then the nonlinear ordinal differential equations were obtained. A hybrid method involving the combination of the Newmark method and the pseudo-force strategy was proposed to analyze the nonlinear transient response of the inclined cable-dampers system subjected to arbitrary dynamic loading. As an example, two typical stay cables were calculated by the present method. The results reveal both the validity and the deficiency of the viscoelasticity damper for vibration control of stay cables. The efficiency and accuracy of the proposed method is also verified by comparing the results with those obtained by using Runge-Kutta direct integration technique. A new time history analysis method is provided for the research on the stay cable vibration control.
文摘As the bridge engineering community sets sails to use longer and longer spans, more and more sophisticated analysis models have to be used in the design process. One of the significant problems represents cable rupture of cable stays. The problem is also addressed in guidelines for cable-stayed bridge design such as PTI （Post-tensioning Institute） Recommendations and EC3 by quasi-static analyses using DAF （dynamic amplification factors） to account dynamic effects, which can be conducted instead ofnsing dynamic analysis. The results show that the value DAF depends on the cable rupture location and on the type and location of the examined state. Dynamic time history analysis is recommended. Some projects examples are highlighted in the paper, where the importance of above mentioned topic has been investigated, following different regulations and approaches. Professional bridge analysis and design sottware solution RM Bridge has been used for all investigations. The application can fulfill all requirements and deliver expected and accurate results. In addition, RM Bridge Sottware also helps engineers as a tool to optimize structure design and increase resistance capacity for each element to ensure the structural safety in service stage.
基金National Science and Technology Support Program of China(No.2009BAG15B01)Key Programs for Science and Technology Development of Chinese Transportation Industry(No.2008-353-332-190)
文摘The problem of geometric non-linearity simulation for spacial cable system was solved by introducing the truss element based on corotational coordinate (CR) system, cable structure materials and node coordinates and automatic refreshing algorithms for element internal force. And the shape-finding problem for maneuvering profile was solved with the Newton-Raphson based on energy convergence criteria with search function. This has avoided the regular truss element assumption extensively used in traditional methods and catenary elements which have difficulties in practical application because of the complicated formulas. The use of CR formulation has taken into account the stiffness outside the cable plane via a geometric stiffness matrix, realizing the 3D space analysis of a cable bridge and improving the efficiency and precision for the space geometric non-linearity analysis and cable structure, and enabling more precised simulation of geometric form finding and internal force of the large span suspension bridge main cable under construction.
