Applied Mechanics and Materials Vols. 578-579

Abstract: Balanced cantilever construction phases are of great importance for the total life cycle processes of super long-span cable-stayed bridges. For assessment purpose, a systematic study on the reliability evaluation of these phases is carried out. Taking Sutong bridge as the sample structure studied, a series of load and resistance models are then established on the basis of field measurement. Using all these achievements, a typical phase of girder segment 6# lifting is chosen for reliability evaluation. Results of the analysis show that the established models are quite representative and reflect actual random nature perfectly. Furthermore, compared with pylon and stay cables the stiffening girder seems more likely to fail in accordance with reliability index. The major failure mode of it in terms of present analysis is the stability failure due to the action of bending and axial load. Nonetheless, the components on the whole are still in a high level of reliability, which can guarantee the proceeding of construction with efficiency.

Abstract: The hill buildings sited on slopes has been widely constructed in mountainous regions. In order to estimate the seismic vulnerability for this type of building under the effect of potential earthquakes, the exceedance probabilities of hill buildings and normal buildings in peak ground acceleration are calculated and compared by using the incremental dynamic analysis method. The fragility curves show the layout of hill buildings has considerable influence on the seismic performance. Specifically, due to the different layout for the hill buildings, the probabilistic characteristic at the collapse prevention level is significantly different from the characteristic of fragility curves at the initial performance level.

Abstract: The mechanical properties of corroded reinforced concrete under repeated load are investigated. The maximum crack width, mid-span deflection and reduction factor are predicted by using support vector machines. The maximum crack width and deflection are predicted by the black-box modeling based on support vector machines with the radial basis function kernel function. The reduction factor is predicted by using piecewise regression formula, whole regression formula and black-box modeling, respectively. The proposed prediction method is verified by comparing all prediction results with the experimental values. It is shown that the proposed method has high prediction accuracy, extensive applicable range and many predictive strategies.

Abstract: Combined with the characteristics of existing lightweight steel structures, the paper gives an adapted method and flowchart for appraisal of reliability of these structures, and explains objectives appraisal of existing lightweight steel structures. It indicates that assessment based on structural analysis is the available method for scientific and saving, according to the demond of market and owner. It also discussed the central technique and the main problems of appraisal in current, such as revision of partial load factors, consideration of conversion factors, etc.

Abstract: To study the durability of reinforced concrete structures under coupling effect of load and environmental, an analog device is developed. Device includes sustained loading, accelerated environmental corrosion and measuring systems. The load applied to the column is real-time monitored by the pressure sensor and compensated according to the stiffness degradation and stress relaxation of column due to the rebar corrosion. Electrode is placed in the column so that the arrangement of the measuring instrument is not restricted. Device successfully realizes monitoring the time-varying mechanical performance degradation of reinforced concrete under the coupling effect of load and environment.

Abstract: This paper made use of nonlinear finite element method to calculate the ultimate strength of bulk carrier model under bending moment and lateral pressure using a commercial FEA program, ABAQUS. It studies the ultimate strength bending moment of Nishihara bulk carrier model. This paper mainly analyzes the influence of the ultimate strength the bulk carrier model under bending moment and lateral pressure laying a foundation for accounting the ultimate strength of the actual ship model in next step.

Abstract: To carry out of out-of-plane stability analysis of plane tubular trusses, nonlinear finite elements model based on spatial beam elements and simplified connection elements is deduced. To verifying the feasibility of the simplified joints stiffness model, numerical examples are build and results shows that the simplified finite elements model is comparatively accurate , and could be used in engineering design.

Abstract: For RC annular members, a new algorithm is derived to calculate bending strength without axial force, and one practical table is obtained to determine the longitudinal reinforcement areas. It is a multipurpose table, because it can be applied to any section size and any concrete strength grade below C50, only one dimensionless form of moment is need, and it provides maximum compression strain of concrete and maximum tension strain of reinforcement.

Abstract: Variational formulation of the problem of the analysis and synthesis of deformable structures are proposed. It allows studying nonlinear problems of structural mechanics from a single standpoint, from a consideration of the General variational principle.

Abstract: This paper introduces the safety appraisal of buildings, how to identify the crack, crack, crack control analysis, is an important work of safety appraisal; and based on the crack causes and characteristics, determine the structure stress conditions, evaluate the structure to make the applicability and durability, security appraisal conclusion.