Applied Mechanics and Materials Vols. 166-169

Abstract: The time-history wind pressure data of the rigid model of an annular large-span cantilever roof of a stadium were obtained by the wind tunnel test. Considering the influence of the vortex shedding, the correlation coefficient and coherence function of along-wind and cross-wind points were analyzed to get the characteristics of the fluctuating pressure correlation of the stadium’s roof. The coherence function curves were fitted and the related coherence function was present. The results show that these characteristics of coherence are all coincide with the correlation coefficient. Compared to the Davenport and Nakamura coherence function models, the present coherence function has the same form with the Davenport and Nakamura's models, and a higher fitting accuracy for the cantilevered roof.

Abstract: Force analogy method is a kind of nonlinear dynamic analysis method. Analyzing inelastic structural behavior by using plastic hinge theory, it is widely appropriate to many structures with different material properties and very time efficient and numerically accurate without complicated iterative computations in traditional algorithm. Compared with the traditional finite-element analysis method, dynamic response analysis based on force analogy method has obvious advantages. The application of force analogy method to a steel structure is presented and the analysis result shows that the method algorithm can represent each response state of the structure in real-time and has the very good accuracy and practical.

Abstract: Axial load loading on the chord can deteriorate impact performance of tubular T-joint subjected to impact loading on the brace. FEA method was used in this paper to investigate the influence of different axial load level under varied impact energy. The analysis result showed that with the increasing of axial load level, the impact force decreased, and under the same axial load level, the impact force increased with the increasing of impact energy. The failure model under different axial load is change from failure around the juncture of chord and brace to at the end of chord.

Abstract: A train-CRTS Ⅲ slab track coupling dynamic model was proposed to study the dynamic performance of the system. Rail was modeled as space beam element. Both slab and HGT layer were modeled as plate element respectively. The vertical and lateral connections between rail, slab, HGT layer, and subgrade were modeled as spring-damper element. The vibration matrix equation of the system was established on the basis of the principle of the total potential energy with stationary value in elastic system dynamics and the rule of “set-in-right-position” for formulating system matrices. The influence of mortar elastic modulus to CRTS Ⅲ slab track vertical dynamic response was calculated when the train runs at 350 km/h. The results show that the larger of mortar elastic modulus, the faster the vibration between rail and slab decays, and the slower the vibration between slab and HGT layer decays.

Abstract: The article analysis the seismic behaviors of circular steel tube composite column filled with steel reinforced concrete by the large finite element analysis software ABAQUS, adopted the load-displacement method and aimed at studying the mechanical properties of circular steel tube composite columns filled with steel reinforced concrete under horizontal low-cyclic loading, considering the degree of ductility, capacity of energy dissipation by the steel ratio and axial compression ratio. Under different axial compression ratios and steel ratios, the hysteresis curves and skeleton curves are carried out. Along with the increase of steel ratio, the deformation ability and ultimate bearing capacity are raised, but with the increase of axial compression ratio, the deformation ability becomes worse.

Abstract: A series of tests on cold-formed steel square and rectangular hollow sections subjected to web crippling is reported in this paper. The web crippling tests were conducted under two loading conditions of end-two-flange (ETF) and interior-two-flange (ITF), which are specified in the current North American Specification for cold-formed steel structures. The concentrated load was applied by means of bearing plates, which act across the full flange width of the specimen sections. Different bearing lengths were investigated. The test specimens were fabricated by cold-rolling from steel sheet with nominal yield strength of 345MPa. The measured web slenderness values of the tubes ranged from 15.5 to 46.0. The test strengths obtained from this study are compared with the design strengths obtained using the current North American Specification, Australia Standard, European Code and Chinese Code for cold-formed steel structures. It is shown that the design strengths predicted by the specifications are either unreliable or too conservative.

Abstract: In this paper ,taking industrial factory building , the size of 33 * 19.8 m² for example, analyzes Integral reinforced concrete floor system under the loads by Finite element analysis software ANSYS. In the calculation process, beam element is beam4, slab element is shell63, Changing the line stiffness ratio of beam and slab, main beam and secondary beam, researches of moment on the main beam and the secondary beam by means of line stiffness ratio. It is showed that , when the value of line stiffness ratio is more than 10, mid-span moment is fewer obviously with the Increasing K ; when the value of line stiffness ratio is between 2 and 5, mid-span moment is fewer, too; when the value of line stiffness ratio is shorter than 2, mid-span moment does almost not changed.

Abstract: This paper addresses the applicability of the provisions of Chinese (GB50018-2002, effective width method) and the AISI Specifications (AISI-DSM, direct strength method) to estimate the load-carrying capacity of cold-formed steel lipped channel columns. It is worth noting that GB50018-2002 and AISI-DSM adopt different approaches to perform this task: while the former is based on the “Effective Width” concept, the latter may adopt the ‘‘Direct Strength Method’’. First, the relevant aspects related to the experimental investigations are briefly presented. Then, an extensive numerical study is performed by them, the estimates provided by them are compared with the experimental values. On the basis of these comparisons, some concluding remarks are drawn concerning the application of the GB50018-2002 and AISI-DSM design approaches.

Abstract: This paper generalizes the research status of passive energy dissipation technology in the field of Structural Engineering. Many achievements has been gotten since its emergence, including the manufacture of dampers, the experimental research and control effect analysis for energy dissipation systems, as well as the studies on its optimal design theory, which plays an important role in protecting people's life safety. However, the current design idea mainly focuses on the security, thus the energy dissipation structures will still suffer great economic losses even in moderate earthquakes. As a result, it is quite necessary to introduce the performance-based seismic design idea to study the design theory for passive energy dissipation. This paper has detailed three key problems in performance-based design of passive energy dissipation and put forward some strategy. Finally, it marks out that to study the performance-based design theory in passive energy dissipation system is of great significance in promoting the sustainable development of society.

Abstract: A1:4 scaled model made of steel is tested on the shaking table. The SAP2000 finite element analysis software is used to analyze the elastoplastic time-history of the model and to compare the results with the experimental data. The purpose of the test is to study the dynamic characteristics of the model’s structure as well as the model’s acceleration response and displacement response in different earthquakes. The experimental and the theoretical analysis basically obtained consistent results tested against each other.