Papers by Keyword: Crack

Abstract: The main defect in concrete and other brittle materials was the crack in the materials which would cause the structures brittle fracture. So it is very important to study the development of cracks in the concrete structure. This article researched the criterion of the shortest distance from the crack tip to the plastic zone edge for concrete and other brittle materials based on the least distance in plastic zone theories. The numerical example verified that the proposed criterion could solve the low stress brittle fracture phenomena in engineering better.

Abstract: Magnesium lightweight wallboard is a new kind of building wall materials in recent years. This wallboard has a light weight, and has the advantages of energy conservation and environmental protection, increase the use area of the buildings, easy to install and improve construction efficiency, etc. This paper designs one 1:1 cast-in-situ concrete frame of span 4.5m and net height 3.3m, and embed magnesium light wallboard in it. Applying level force with simulates wind load to the wallboard. In the experiment adopted two wallboards with different thickness and different connection ways with wallboard and frame. During the test observe the development of cracks, measured the horizontal displacement, the cracking load and ultimate load of wallboard. Test results show that the strength and displacement of wallboard can satisfy the requirements of the use of exterior walls, which can be used to building external wall with a certain height.

Abstract: This paper is based on the basic principles of the extended finite element in the large commercial software ABAQUS on the platform of different fracture energy of three point bending test of concrete are numerically simulated, and three-point bending crack initiation, through expansion path analysis. The results show that has a direct impact on the size of the fracture energy of concrete specimens destruction, Fracture of brittle fracture can be small more obvious, produce more harmful. When softening decline stage after peak stress occurred in the "jump back" phenomenon.

Abstract: Blasting-induced seismic wave imposes cyclic loadings on adjacent buildings and structures with a combined loading mode of tension, compression, bending, shear and torsion, and it leads to flaking of floated coat, wall cracking, developing of original cracks, etc. This paper presents a blasting case study for the excavation of Wucun tunnel in Xiamen Success Avenue. Field monitoring and numerical calculation of a typical brick masonry structure are adopted to analyze the relationships among the maximum structural displacement, peak vibration velocity of blasting-induced foundation vibration and the change rate of crack width. On the basis of the study above, a method of calculating the safe vibrating velocity for single-layer masonry structure is proposed. Meanwhile, a suggested value of the safe vibrating velocity for single-layer masonry structure is given. All the research results can be useful for the similar construction and research.

Abstract: Swelling and shrinkage due to moisture-change is one of the expansive soils characteristics, which is similar to the behavior of most materials under thermal effect. The stress is defined as moisture-change stress and is adopted to analyze swell-shrinkage deformation based on the elasticity mechanics theory. A FEM program is established which is used to calculate the stress caused by moisture-change considering the defect of theoretical calculation. The stress via FEM program can be accordance with the actual characteristics and the moisture-change is more applied extensively.

Abstract: The combination of a number of construction experience, which is based on the analysis of different parts of the fly ash foam composite light wallboard wall cracks. Appropriate preventive and remedial measures were put, specific elaboration was done, which were used to guide practice and reduce light wallboard wall cracks.

Abstract: In this paper,in order to study the load-bearing capacity of frame columns with construction joint under low-cyclic reversed loading, nine specimens were made, divided into three groups.Every group had three specimens, the first were made without construction joint, the second had fine processing construction joint, the third had simple processing construction joint. The three groups were loaded in axial compression ratio of 0.23,0.34,0.46 respectively.The results show that the influence of different processing with construction joint to crack position ultimate bearing capacity,skeleton curves.

Abstract: It is supposed to be constructed a kind of profiled pipe culvert which have a new type of cross, in view of the reinforced concrete circular culvert's various diseases that occurred in service of it. In order to know about the mechanical characters of structure, and test the carrying capacity of the profiled pipe culvert, the load test can be used to have a research on the stress, deformation characteristics, and crack distribution and development on the profiled pipe culvert.

Abstract: This article focuses on a cracking steel crane girder of one factory, on the basis of extensive investigation and research on the fatigue damage of cracking steel crane girder at home and abroad. Sectional stress is redistribution and the stress concentration phenomenon of the crack tip has been alleviated. After reinforcement, the local stiffness of the upper flange and web greatly increases, The results show that it can extend the fatigue remaining service life of fatigue cracking of the steel crane girder by increasing the effective cross section area and stiffness, and it is a good guide on reinforcement and maintenance of actual industrial plant cracking steel crane girder.

Abstract: With the fast development of economy, science and technology, concrete has been widely used in bridge construction. But the problem of concrete bridge structure crack is still an important issue in bridge construction in China. How to combine the bridge foundation theory with the practice of construction to solve the problem of concrete bridge structure crack is the key to guarantee the quality of bridge construction. This paper focuses on the cause analysis of concrete bridge structure cracks and the treatment countermeasures are put forward.