Papers by Keyword: Longitudinal Crack

Abstract: The present paper deals with an analytical study of the time-dependent delamination in a multilayered inhomogeneous cantilever beam with considering of the loading history. The multilayered beam exhibits creep behaviour that is treated by using a non-linear stress-strain-time relationship. The material properties are continuously distributed along the thickness and length of the layers. The external loading is applied in steps in order to describe the loading history. The analysis reveals that during each step of the loading, the strain energy release rate increases with time. The influences of crack length and location on the time-dependent strain energy release rate are also investigated.

Abstract: The present paper analyzes the influence of creep on longitudinal fracture in continuously inhomogeneous rod of circular cross-section loaded in torsion and bending. The rod exhibits continuous material inhomogeneity in both radial and longitudinal directions. The creep is described by using non-linear time-dependent relations between the principle stresses and strains. A time-dependent solution to the strain energy release rate is derived by analyzing the complementary strain energy. The time-dependent strain energy release rate is found also by considering the energy balance for verification. The solutions are applied to perform a parametric study of the strain energy release rate under creep.

Abstract: Longitudinal crack in bottom flange is one of the most common defects in concrete box girder bridges. This paper focuses on the influence of the longitudinal cracks on the mechanical properties of box girder using numerical method. Smear crack model and strain softening model was employed to simulate cracking process. Parameter analysis was also carried out to study the effect of length, crack depth and amounts of cracks in bottom flange. The results indicate longitudinal cracks in one span have a significant effect on the transverse stress and deflection, but have little effect on the other spans. The negative effects of longitudinal cracks increase with the crack length and depth. When the crack length is up to 10% of the girder span, the deflection of the span amplifies to 13%. Compared with the length and depth, the amounts of cracks don’t have much influence on the deformation of girder but affect stress.

Abstract: This paper presents a three-dimensional entity model to analyze the creep effection of PC continuous rigid frame bridge and simulate the impact of longitudinal cracks at the bottom of mian span on the deflection briefly with ANSYS software. The result shows that creep amplifies the deflection of bridge and makes the position of maximum deflection move to the center of mian span. And the longitudinal cracks of mian span don’t make great contribution to the deflection of PC continuous rigid frame bridge directly. Actually, the cracks change the stress state of the bridge’s section, which results in the risk of web cracking and further the stiffness degradation of structure. The stiffness degradation increases the defection of bridge to a great degree finally.

Abstract: This paper presented a method of building the view image for Driving Simulator based on various road profiles and crack information by considering the damage road such as roughness road and crack. The main property of this method is that we can obtain the data profile only from several photographs of the road. Therefore, it is flexible and efficient.

Abstract: Prestressed concrete hollow slab bridge is widely applied in the highway bridge in our country, this paper shows that longitudinal crack appeared earliest in the defective component parts based on the test of 30 m span real bridge under plate cyclic loading experiment. The test data show that at the initial stage when the load is low and crack width is narrow, cyclic loading does not exerts an influence crack development, and when the load increase and crack expand to a certain level, cyclic loading exerts an influence crack development visibly. The discipline between the crack width with loading process is also studied, and the conclusion is helpful to understand load cracking behavior under cyclic loading and damage accumulation and performance of bridges.

Abstract: Longitudinal crack is one of the main subgrade diseases of qinghai-tibet highway and has large scale.While the existing treatment technology cannot completely solve the problem,especially cannot limit crack propagation,so the driving safety and road life will have huge influenced by the disease.In order to solve this problem,a new solution technology that the flexible beam combined with tenon type geomembrane bag is proposed in this paper.Through field implement,this new method which can effectively reduce and prevent crack diseases is verified.

Abstract: The cable-stayed bridge which has been found longitudinal cracks in tower is taken as the background, combining with the original design information and the results of bridge inspection. The numerical simulation on temperature effect of cable tower has been done with MIDAS/Civil, and the results have the same trend with observed in bridge inspection, indicating that the cracks in tower probably are caused by temperature effect. Then, some suggestions are raised in the end of this paper about how to deal with these cracks. This work could be a valuable reference for similar large cable-stayed bridge. And the temperature stress should be paid more attention in design process to avoid appearance of temperature cracks which affect beauty and durability of structure.

Abstract: Overlay new cement concrete pavement on the old cement concrete pavement following different treatment schemes, survey pavement cracking phenomenon after the opening of the new pavement , analysis the crack resistance of the various programs, accumulate experience for the cement concrete pavement repair technical solutions.

Abstract: This paper presents a study on reinforcement of timber columns with longitudinal cracks strengthened by CFRP sheets under eccentric compression. An experimental program using special eccentric compression hinged-support was proposed to identify the failure modes and to investigate the recovery in load carrying capacity. Different combinations of eccentric distance and directions of the eccentric plane related to that of the crack plane were considered. This test can provide detailed experimental data for the application of CFRP strengthening on timber columns under eccentric compression which is an efficient method to maintain the original historical structure.