Applied Mechanics and Materials Vols. 193-194

Abstract: In this paper, conducted a systematic study of thermal performance of steel mesh frame sandwich insulation board. The thermal performance of steel mesh frame sandwich insulation board was determined under different conditions. Proposed the insulation effect on oblique inserting wire in the steel mesh frame sandwich insulation board and provided the basis for engineering design and application.

Abstract: Some calculated methods of shear capacity of RC beams strengthened with NSM(near-surface mounted) CFRP(Carbon fiber reinforce polymer) rods are reviewed based on the experimental data on shear capacity of RC beams strengthened with NSM CFRP rods. Therefore, according to the destruction forms of steel reinforced concrete beam strengthened with NSM CFRP rods, the formula for calculating the shear capacity of the beam is given. The formula is expressed clearly, simple and easy to use.

Abstract: The prestressing wires of prestressed concrete cylinder pipe (PCCP) provide pipe wall with compressive stress to resist internal pressure. Broken wires resulting from corrosion is a major factor contributing to the degradation of pipe strength. In order to analysis the failure process of PCCP with broken wires, a 3-D model with a very fine mesh is developed for the pipe structure, considering material nonlinear behavior, pipe-earth interaction, prestress loss, and combined effects of external and internal loads. The results of nonlinear finite element analysis show that wire breaks causing prestress loss can accelerate the failure process of PCCP. As internal pressure increases, the earliest concrete cracking and steel-cylinder yielding occurs in the prestress loss zone. The closer to the prestress loss zone, the higher stress unbroken wires will have.

Abstract: Xigeda Soil, as a kind of typical soil widespread in west region of Panzhihua, is widely applied to local engineering construction. Limesoil made by adding quicklime into Xigeda soil is also extensively used in wall construction of rural house building. The strength of wall material of Xigeda limesoil wall is measured in this paper through contrast test, meanwhile, strength of rammed limesoil with 1:9 volume ratio is measured on 60th day and 36th month respectively. The test result indicates that compressive strength of limesoil increased by 67% and its tensile strength also greatly increased, which is beneficial to its application in wall engineering construction. This paper also makes an analysis of limesoil mechanism of cementation and points out that Xigeda limesoil is a favorable wall material for house building.

Abstract: The design and analysis of the large span steel latticed shell structure in site of Yuyao TianLuoshan is introduced, and some key problems are dwelled on in this paper. By the geometrical nonlinear finite element method, the nonlinear stability analysis is carried out. The buckling modal and the whole course of instability are shown by two analysis method, the eigen-buckling analysis and the geometrical nonlinear finite element method. The influence of spring support to the stability of the structure is analyzed. It is shown that the structure has good wind-resisting capacity, which is fit to the circumstance near sea with lots of typhoon. Large compressive membrane stresses arise in the structure under the condition of temperature rise, leading to a significant reduction in the stability load-carrying capacity of the structure.

Abstract: How to judge the dynamic instability of trusses is an important problem. It is found that stress rate of a truss has the catastrophic characters when trusses are out of stability. According to the relationship of the total strain energy and the stress rate, the principle of stress rate is proposed , that the dynamic instability was made in structures if the stress rate was suddenly changed to a relative very great value. Some examples, such as a dome shell, a three-bar spatial frame, a plane truss, and so on, are discussed. The results showed that it was effective to judge the instability of truss structures by using the tress rate criterion. By comparison of the stress rate criterion with the displacement criterion it can be obtained that the result of displacement criterion was comparatively obvious in the global instability while the result of stress rate criterion was more ocular in judging the local instability in truss structures.

Abstract: The ultimate bearing capacity of the single-layer latticed shell structure, calculated without considering the single-member instability(P-δ effect), was not consistent to the actual value of ultimate bearing capacity in practice. It was studied in detail that the ultimate bearing capacity of the single-layer latticed shell structure considering the member instability by proposing a method of multi-element simulation. The value of the ultimate bearing capacity decreased by 15.6% after considering the member instability taking a single-layer latticed shell structure with a 40m span as example. The analysis results show that the value of ultimate bearing capacity is significantly affected for the single-layer latticed shell structure with a small span and high rise-span ratio

Abstract: Beijing South Railway Station is an integrated system, the evaluation of which should involve not only the inner transfer condition, but also the connection in the road network. To make a more comprehensive and scientific evaluation of the station, we select various criteria, including not only the static indicators, but also the dynamic indicators. Then we build a three-level hierarchy index structure to evaluate the performance of the inner and outside performance of Beijing South Railway Station. For the inner part, we apply Extension Theory to for evaluation. Then we use VISSIM to simulate the condition of the station in the road network.

Abstract: Recycled concrete is a kind of green and new material. With the application of construction, more research should be carried on its carbonization performance, not only focusing on its mechanical properties. Recycled concretes with different W/C (0.45、0.55 and 0.65) and recycled aggregate mix proportions (0、30%、50%、70%and 100%) are made to test their carbonation depth. The results show that water-cement ratio and recycled aggregate mix proportions have interactive influence on carbonization performance of recycled concrete. Influence of recycled aggregate on carbonation depth depends on two conflicting aspects: one is beneficial effect due to high water absorption; another is harmful effect caused by damage structure. A new model of RAC carbonation depth is suggested based on the study.

Abstract: The appearance of commercial concrete has heightened architectural construction level, improved construction civilization and offered the guarantee of the popularization and application of new tech significantly. Meanwhile, its popularization has brought the issues of structural solid concrete strength test and early plastic cracks. Currently, the solution for commercial concrete structural strength test is mainly done by means of method of non-destructive test of core-drilling correction. Merely the primary analysis can be done over the early plastic cracks to find no reasonable explanation toward those cracks, nor define the responsibilities of the related subjectival responsible parts that cause the cracks.