Applied Mechanics and Materials Vols. 438-439

Abstract: This paper aims to experimentally study static responses of bridge longitudinal truss, and the distribution rules of the structural and local stresses were analyzed. The results of the analyses on experimental data show that the typical details in the longitudinal truss concentrate to a limited area on the toe of a dominate weld at the intersection among the upper chord or bottom chord, diagonal and the gusset plates; with boundary conditions being strengthened, stress distribution of the tested specimen became flat and the monolithic tress level decreased relatively. Based on obtained test information, the results are used for updating and validating this kind of structural model, and determining the parameters of finite element model.

Abstract: The goal of the paper is to make good use of solid wastes. The aggregates of ordinary self-compacting concrete are changed for the large size of recycled aggregate, which are randomly put into the mold before self-compacting concrete are poured into to form the new type of concrete specimens, and a freestone aggregate specimen is also made for a comparison. 500 tons of electro-hydraulic servo testing machine is used for the test, to measure the strength of this new wall material, bearing capacity, deformation properties and damage form, etc. Test results show that the average compressive strength of the wall of recycled aggregate rock-filled concrete is 6.42MPa, which is far greater than 2.03MPa specified in standard under same mortar strength. Therefore, the recycled aggregate concrete wall of self-compacting has higher bearing capacity, and can meet the requirment of the project.

Abstract: Based on plastic limit equilibrium theory of soil, the suitable values of energy safety factor are discussed here from energy work rate, the new design method for vertical slope of deep foundation pit with layered soil braced by soil nail with even overloading on slope top is proposed and engineering example is given out.

Abstract: Joint design point is an important concept in reliability analysis for parallel structural system. The paper proposes an asymptotic approach specialized for finding joint design point, and gives the examples to illustrate the application of this approach.

Abstract: Space truss structure is widely used in various engineering fields. The key technical problems are mechanical analysis of its structure and optimization of the design of truss structure. In this paper, comparison of the four different designs of the concrete transport truss structure system based on ANSYS, and the FORTRAN procedure were programmed. Finally both practical and economical factor was chosen to meet the engineering truss structure. These results should be of guiding significance to design and construct retaining engineering in space truss structural.

Abstract: The damage diagnosis theory and method of engineering structure is one of the hot issues concerned by the engineering circles at present. Based on the strain modal analysis theory, it expounds the connection among displacement mode, strain mode and curvature mode, with a heavy rubber as the material to make a cantilever beam, and establishing the different damage conditions of the cantilever beam, studying about dynamic structural damage identification under the incentive, which provides the theoretical basis and technical support for the research on damage detection of large engineering structure.

Abstract: Generally laminated wood frame beam-column uses the additional steel bolts to connect, its performance is a semi-rigid characteristics under the loads. In the small deflection assumption conditions, this paper is based on the theory of semi-rigid connection, derived the semi-rigid rod end stiffness matrix and moment calculation formula of laminated wood structural frame beam-column element under the arbitrary loads. By SAP2000 the type of flexible coefficient is adopted to establish finite element numerical analysis based on 1# wood frame structure-building of science and technology R&D center in Hebei province. The result shows that each component is basically the same with the original design internal forces while the flexible coefficient is range of 0.41 to 0.82, the framework of semi-rigid connections in the actual calculation should be considered. The internal force calculation method is proposed, which provide a basis for wood design calculation that takes into account the semi-rigid connections.

Abstract: By the experimental studying on the basic mechanical properties of recycled concrete hollow block masonry, the compressive and shear behavior of recycled aggregate concrete hollow block masonry under different mortar strength were analyzed. Research indicated that the compressive and shear behavior of recycled aggregate concrete hollow block masonry was similar to that of ordinary concrete hollow block masonry. The normal formula was recommended to calculate the compressive strength of the masonry. The shear strength of the masonry was affected by the mortar strength. The shear strength calculation formula of recycled concrete hollow block masonry was proposed according to the formula of masonry design code. The calculating results were in good agreement with the test results.

Abstract: Based on a practical project, the dynamic parameters for a 4-story reinforced concrete frame, with additional different stories of steel frame constructed on its top, are investigated, including vibration period, frequency, and seismic response under minor shock, such as inter-story maximum horizontal displacement, inter-story maximum horizontal displacement angle, inter-story shear force and so on. It reveals that the maximum number of additional stories may be determined by the inter-story maximum horizontal displacement angle. With the additional steal frame adding on the top of the original structure, the maximum horizontal displacement angle often comes into being as the second story from the top of the structure, at the same time, a certain story in the prototype structure may evolve into a weak story which has to be reinforced. However, with the increasing of additional stories, the total shear force in the bottom story decreases, which leads to a new anti-seismic design concept.

Abstract: Mode is the inherent property of structure, and any action response can be decomposed by mode matrix. Through the mode expansion, each mode direction parameter can be clarified, and the designer can elevate the good response and cut down the bad one. So the designer has capacity that assesses the whole structure property by the mode analysis, and guides the concept design and mechanical design.