Applied Mechanics and Materials Vols. 275-277

Abstract: Based on the features of lifting construction of prefabricated structure, propose a new type of temporary bracing of prefabricated column, and analyze the two different structural forms of the traditional prefabricated column bracing frame and the new prefabricated column bracing frame by finite element software ANSYS. The results show that the new precast column support frame have a better stability and stronger lodging resistance

Abstract: It was optimized that the lateral stiffness of an under-designed super high-rise building located in 0.30g seismic fortified regions, with 58 stories above the ground and 235.80 meters total structural height. By having adequately adjusted the wall thicknesses of the core-wall and the cross sectional dimensions of the frame columns, a more reasonable structural scheme was obtained. It was then discussed the suitable numbers and heights of the strengthening stories set for controlling the building’s story drifts. Finally, it was explored that the efficiency of seismic input energy dissipation via viscous dampers installed at the right places of the structure.

Abstract: Moisture transportation is a key factor to affect the long-term safety of underwater concrete tunnel. According to the inside and outside environment of tunnel, the moisture transportation equation in unsaturated concrete of underwater tunnel was raised. Finite difference method was adopted to solve the nonlinear partial differential equation of moisture diffusion. The study shows that the changes of water saturation in concrete are mainly concentrated in the surface of tunnel wall and amplitude is gradually slowing down over time. Saturation changes greater in the outside than inside. The wetting state is more obvious than drying state.

Abstract: This paper briefly introduced the cylinder pressure - injection synthesis method which is detection masonry structure mortar strength technology principle, the technology based on the mathematical statistics method for data correction processing, and it combines the advantages between cylinder pressure method and penetration method ,and this method and more accurate and reliable than a single detection technique.

Abstract: In order to improve the mechanical performance of timber beams, five rectangular-section beams were used in flexural test and ten for shearing. The effects of FRP types i.e. CFRP, BFRP and AFRP, layers of FRP sheets and the way FRP sheets pasted were studied. The failure pattern, load-deflection curve, strain distribution and ultimate load capacity of the specimens were analyzed. The results indicate that the ultimate load carrying capacity of beams were increased by 15.4% to 55.1% varyingly with the reinforcement of FRP, besides, the stiffness and ductility were improved also. The improvements were lower in the specimens with material defects such as the existence of knags and shrink cracks. It’s more effective to paste the FRP sheets slantingly with the angle of 45° than vertically. However, the effect on the initial stiffness is not distinct whether reinforced or not. The analysis of strain and stress distribution manifests that the plane cross-section assumption is efficient in design and calculation of FRP reinforced timber beam.

Abstract: Ansys, the large-scale general FE program, was used to establish computational models of 3×16m-long integral abutment skew bridge with different skew angle to analyze the mechanical characteristics of pile base under the temperature load. Through the analysis of parameters, some helpful conclusions, which would pave the way for further exploration on mechanical behavior of integral abutment skew bridge, were reached.

Abstract: In order to further study the mechanism of adaptive-slit shear walls under horizontal loads, and facilitate it better applied to practical engineering. On the basis of experimental studies, the ABAQUS finite element analysis software is used to establish the finite model of adaptive-slit shear. The finite element model accuracy is verified by comparing the model and test results. A validated model is used to study the mechanical property of adaptive-slit shear walls under monotonic loads.

Abstract: There are no conventionally accepted failure criteria for progressive collapse, and often times, deflection of affected beams over the “missing column” are often used as performance criteria. However, when simulating the deformation behaviour and the strength of reinforced concrete (RC) framed structures for progressive collapse analysis, besides the flexural deformations, the so-called “fixed end” rotation induced by the longitudinal bar slip at the beam-column ends connected to the joints can be significant and result in additional lateral deformations not accounted for in the initial analysis. Hence, it is important to quantify the deformations arising from fixed end rotations. Several bond stress-slip relationships between steel reinforcement and concrete were previously proposed in the literature. In the present work, their merits and demerits are discussed in terms of application limitation. To address the limitations of previous bond-slip models, a new analytical model based on the bond stress integration along the bar stress propagation length is proposed to predict the bar-slip behaviour in the RC beam-column joints. The proposed analytical model on the bond stress-slip relationship is validated against experimental studies from the literature and is shown to be simple and reliable.

Abstract: Triaxial compressive tests were performed on laterite clay(LC) reinforced with different fiber contents and lengths. It was observed that the curves of stress-strain have a segmented characteristic at the critical strain. The stress-strain curves of fiber reinforced laterite clay(FRLC) were expressed by the combination of hyperbola and straight lines. The parameters of stress-strain curves were obtained by linear and nonlinear fitting method with experimental results. A three-dimensional calculation model of triaxial tests was developed on the basis of ABAQUS software. To express the stress-strain relationship of hyperbola-straight lines, user’s subroutine was established through secondary development. Based on the test conditions, a large number of calculations were conducted. There is a good agreement between the results of numerical calculations and tests. It shows that the stress-strain relationship of FRLC can be described by the hyperbola-straight line combination model.

Abstract: The fatigue life prognosis of concrete is becoming more important with the development for demanding higher quality and safety in industrial. However, effective methods for this prognosis are still in need now, due to the feature of concrete. This paper proposes the extended grey Markov model (i.e. EGMM) for fatigue life prognosis of concrete. Firstly, the GM (1, 1, λ1, λ2) (i.e. EGM) is proposed by integrating the particle swarm optimization algorithm (PSOA) with GM (1, 1) (i.e. GM). Then the Markov model is integrated with EGM and a novel prognosis method of the extended grey Markov model is proposed. The EGMM is used to combine the health states and transition probability. And a real case study is used to demonstrate the implementation and potential applications of the proposed fatigue life prognosis approach on concrete.