Research On Equivalent Elements For Reinfoced Concrete Briges

Along with bridge construction enterprise vigorous development, new bridges mechanics performance whether did achieve design request, old bridges bearing capacity whether does satisfy the safety requirement, all needs to carry on the health monitor to the bridge. The bridge finite element computation will play a more vital role in the bridge construction.The model composing the reinforced concrete structure finite element method at present has two kinds mainly, one being to choose the steel bar element and the concrete element to establish the entire bridge unit, namely separation-type model. One kind selects the reinforced concrete unit, namely the supposition steel bar distributes in the entire unit to establish the entire bridge model as steel bar unit and the concrete unit's equivalent unit, namely integral-type modeling.This article take Luo Jia gang bridge as the research object, used two models ways to carry on the numerical analysis discussion for pre-stressed reinforced concrete bridge, and moved the load test result with the corresponding actual bridge to carry on the comparison, obtained some main reference values results, for the next design, the finite element simulation simplification will provide the instruction. Below this article mainly completes works:(1) Introduced the theoretical basic of space FEM in details, elaborates the reinforced concrete synthesis unit rigidity matrix, material's construction relates and strengthening model, pre-stressed simulation.(2) Carries out a static test on Luo Jia Gang according to loading at the most disadvantageous location. Get entire bridge deflection and strain numerical value in wanted key. get three order frequency of entire bridge by dynamic test.(3) Choose the reinforced bar element and the concrete element to build up entire bridge element to imitating the bridge. Get entire bridge deflection and strain numerical value in wanted key and the first three steps frequency of entire bridge; next use integral type model(namely with reinforced concrete equivalent unit) to build up the spatial finite element model, carries on the value simulation to this pre-stressed reinforced concrete bridge .(4) Finally, comparing the two computed result of two kinds of model,analyzes the merit and the shortcoming of establishing the model with the equivalent unit and the result of the disparity. Finally found the bridging the gap between the method.The research of this text has the certain value such as discussing the equivalent unit in bridge analog computation, going deep into acquaintance bridge structure characteristic , improving the precision of finite element computation of ANSYS.