Test And Finite Element Analysis Of Unbonded Prestressed Simply-supported Concrete Beams

Since 1980s, the technology of inner un-bonded prestressed concrete structures has been extensively used in the field of civil engineering .The scholars, in the domestic and foreign countries, have been expanding extensive research works,have obtained massive research results in both static performance and the design calculation about inner un-bonded prestressed concrete, and many achievements have been used to instruct the project practice. With the constructional engineering discipline development, the dynamic analysis and the simulation of construction has becomed necessary for the health examination and monitor of engineering structure. So the finite element dynamic analysis about prestressed concrete simple beam will be carried this paperIn the paper, correlated finite element theories about the stress-strain relationship of concrete and the stress-strain relationship of reinforcement have been summarized. The key technical questions about the finite element analysis of the reinforced concrete structure, including the unit model choice, prestress tendons coupling as well as the prestress force simulation, have been discussed and explained.The topic group has carried out the dynamic experiment of three inner un-bonded prestressed concrete beams. The dynamic performance and particularity of their have been analysed and generalized through the natural frequency acted by different pretress forces. The results indicated that in a range, the frequency of beam increased when the prestress force value increased; Greater than the some definite prestressing force, the frequency of beam increased along with the prestressed force reducing. Generally, the frequency of beam increased with the prestressed force increasing.The dynamic performance about the prestressed simply supported beam used in the experiment has been analysed through model building. In view of the concrete material particularity, the material non-linearity of concrete and the orthotropic, the frequency of beam carried on experimented has been calculated by many kinds of construction relational models. They has indicated that The frequency of the prestressed simply supported beam is influenced by prestress force. The calculations,according to the traditional constitutive equations about reinforced concrete construction ,do not agree with the test results, so the new constitutive equation ,which is used to analyze prestressed concrete structure ,is extremely important.