Applied Mechanics and Materials Vols. 275-277

Abstract: This paper applied nonlinear elastic theory to the cable structures, presented a finite element method with six-node isoparametric element, used the polynomial of degree five as displacement functions and initial curve of the element. Assuming the cable to be ideal flexible, by means of Lagrangian method, the finite element equations has been derived, so can use this method to compute cable structures.

Abstract: In order to find out a new way to get the principles of the main girder alignment long-term changes and estimate the technology level, the main girder alignment variation was monitored by the real time monitoring system. Then the monitoring data was analyzed depend on the assessment theories which based on the statistical characteristics of the monitoring data. For the large amount of collection data, the convenient of monitoring data and fast processing could be realized by using the Matlab programming software. The analysis results show that the assessment theories can well realize the girder alignment evaluation; the main girder in the monitoring period shows a small alignment changes, girder technology level is in a good condition.

Abstract: Based on full-scale sectional model experiment for cable pylon anchorage zone of cable-stayed bridge, this research tested the friction factor and deviation factor of the duct. The reason that tension elongation of loop prestressing tendon exceeded the provision of ±6% in specification was analyzed systematically. A correctional calculation formula was proposed, with quantitative analysis for influencing factors of tension elongation. The formula shows good applicability in practical engineering and has reference value for similar loop prestressing tendon.

Abstract: Taking an large-scale PC frame structure as example, the Finite Element simulation of structure construction procedure are performed, prestressing restraint effect, seasonal temperature variation and concrete shrinkage & creep effects are considered. The results show that the displacement and interior force of structural members can be significantly influenced by taking different construction procedure.

Abstract: Stability problem of gravity retaining wall structure was researched, and a simplified formula of the active earth pressure Ea was turned out for the convenience of the program design. The anti-slide safety factor K0 and anti-overturning safety factor Kc were derived based on different positions of slip plane of retaining wall. This work is the basis of the reliability calculating and program design, for these formulas must be used in anti-slide and anti-overturning safety failure mode in program compiling. On the basis of the known parameters such as wall type, wall dimensions, material parameters, external load, and so on, the program can automatically calculate K0 and Kc, their corresponding failure probability Pf and reliability index β can easily be calculated in later analysis. The research content provide a convenient calculation method, which is used to calculate the Ea and K0 and Kc and Pf and β of the actual retaining walls engineering.

Abstract: Shell elements were used to simulate the wide box girder of arch bridge. Different load cases on the arch bridge were calculated and the stress distribution pattern of the wide girder was obtained. The results show that the stresses of the top plate and the bottom plate are non-uniformity along transverse direction at same section, the maximum non-uniformity coefficient of the top plate and the bottom plate are 1.89 and 1.73 respectively. To arch bridge with large ratio of width to length, the transverse stress of girder should not be neglected and the combined stress should be used to determine the structure safety.

Abstract: Orthotropic steel deck; Shear nail; Steel fiber concrete pavement layer; Stress analysis. Abstract. Aiming at the optimization design of composite pavement on orthotropic deck in a streamlined steel box girder with lager wide-to-span ratio, finite element analysis is taken under various loads supplemented with static model; the stress distribution is analyzed in each part of the pavement layer. The theoretical results show that the deck of the bridge displays obviously orthotropic features; shear nails with reasonable density can increase the binding capability of each part of deck pavement and overall mechanical performance. It can be concluded that the service life of the deck pavement can be extended by the use of steel fiber concrete layer.

Abstract: Based on independent research and development of a CFRP tendons wedge-type anchorage, the shear tests of six CFRP external prestressing concrete beams were done. Among them, CFRP external tendons of three pieces were installed in straight line while other pieces were installed in curved line. The results of experimental research show that shear behaviour of concrete beams prestressed with CFRP external tendons are the similar process to the traditional prestressed reinforced concrete beams. They go through the elastic stage, the stage of crack extension, the yield stage of internal hoop reinforcements at the intersection of inclined cracks and the failure stage. When external CFRP tendons are arranged in the same situation, the cracking load and the shear capacity of concrete beams prestressed with CFRP external tendons reduce gradually along with the increase of shear-span ratio,.When shear-span ratio is equal, the cracking load and the shear capacity of concrete beams prestressed with curved arrangement of CFRP external tendons are larger than those of concrete beams prestressed with straight arrangement of CFRP external tendons. Compared with traditional concrete beams prestressed with external steel bars, due to elasticity modulus and shear modulus of CFRP tendons are both smaller than those of steel bars, the mid-span deflection of concrete beams prestressed with CFRP external tendons at the time of shear failure is bigger than that of traditional concrete beams prestressed with external steel bars under the same circumstance.

Abstract: Natural frequencies of bridges have certain sensitivity to prestressing force, so the identification of effective prestressing force based on bridges' natural frequencies is a effective method. This paper uses Finite Element Methods to establish the finite element model of prestressed steel beam, and then conducts dynamic simulation analysis of the natural frequencies of the simply-supported bridges on the condition of different prestressing forces and different reinforcement eccentricity distance arrangements. Based on the results, it analyzes the law and the extent of prestressing force's influence on the natural frequencies, and at last makes the quantitative relation of the prestressing force and the natural frequencies of the bridges. It supplies the theoretic support for the identification of effective prestressing force in the prestressed simply supported beams.

Abstract: Based on the needs of housing industrialization, prefabricated experimental study on performance of shear wall structure is essential. This article describes the specific steps 、experimental data processing method and finite element analysis of prefabricated shear walls and cast shear wall under the low cyclic reversed loading. It is to solve the error of the measurement results from error experimental methods of operation. Finally, we also look forward to the expected results of the comparative test of the shear wall structure.