Abstract: Most aluminum alloys used for structural purpose are either heat treated or cold worked in order to develop higher mechanical properties. When alloys with enhanced properties are welded, the heat of welding reduces the strength in localized regions (named Heat Affected Zone) in and immediately adjacent to the welds, which makes the study of the bearing capacity of welded beams become more complicated. Nowadays it will be long time and cost much if only through experimental method to study the welded aluminum beams. Thus a finite element (FEM) analysis method is tried in the paper. By comparison the test results gotten with the ones of the FEM analysis, it is verified the feasibility of utilizing it to study the welded beams. Furthermore, a large number of results produced by this method validated the formula proposed in China aluminum code.
Abstract: In order to solve the problem that traditional main building for large thermal power plant cannot satisfy seismic requirements in high-intensity area, we put forward SRC frame-RC few shear walls structure system to conduct experimental study and theoretical analysis. Based on pseudo-dynamic test of 1/7 scale model and elastic-plastic time history analysis, the deformation property and capacity for dissipation of energy, as well as the failure mechanism are analyzed. The results show that the new structure system has well seismic performance, it can satisfy seismic fortification goals in 8 intensity Ⅱ zones, but the weak positions should be given enough attentions.
Abstract: This paper presents a method that using inner transverse prestressing bars to enhance the shear capacity of concrete beams, which can be used in new transformer beams to decrease the sectional dimensions. Four transversely prestressed concrete beams and one ordinary reinforced concrete beam were tested. The nonlinear finite element method was applied to analyze them, and the following conclusions can be drawn: (a) The transverse prestressing bars can efficiently increase the shear capacity and failure load of the reinforced concrete beam, the improvement effect is more obvious when exerting the prestressing force on them properly. (b) On the whole, the simulated load-deflection relationships and failure loads of the five specimens agree well with the corresponding tested load-deflection relationships and failure loads. It indicated that the FE models used in this paper predict the structural behavior of the transversely prestressed concrete beams satisfactorily. (c) From the contour of first principal stress, it can be seen that the transverse prestressing bars can efficiently enhance the shear crack resistance of the reinforced concrete beams, if the area of transversely prestressing bars is almost same, the transverse bars with smaller diameter and smaller spacing will be better. It agrees well with the test results.
Abstract: The suspend-dome structure is designed for the steel roof of Pingshan Basketball Gymnasium for Universidad 2011 Shenzhen, the overlapping diameter is 72m, supporting by 24 RC columns evenly distributed along the periphery. The following analyses were carried out: the design criterion of the suspend-dome; the linear and nonlinear buckling analysis; the detail analysis of the complex key joint, the arrangement analysis of the suspending chord and the prestressed cable; the construction stage modeling and construction scheme analysis. The key issues and relevant construction method were summarized, which could be used as reference in the similar design.
Abstract: The engineering pricing model has changed a lot since the implementation of pricing norms, especially the advocacy of unit price contract in the revised norms. It greatly affected the cost of the project's completion by the accuracy of comprehensive unit-price. This has brought great challenges to the bid evaluation. The experts of initial analysis of bidding identify problems analyze the reasons and give professional guidance by the check and analysis to bidding documents. This work can give advance to the bidding experts and owner; also can improve the quality of bid evaluation. The initial analysis of bidding is the trend of bidding evaluation in the future.
Abstract: Take the roof of the palace timber structure as the study objection, according to the requirements of the Ying-tsao fa-shih, it establishes the model. Through the analysis of the dynamic properties with ANSYS finite element software and shaking table test, it gets the structural dynamic properties and its maximal response under different conditions, and abstains the seismic amplification coefficient of the beams layer and the whole structure, compares the results reached by shaking table test with the numerical simulation. Research shows that the nature frequency of the model is 1.486 Hz; the roof’s nature frequency is much bigger than that of the whole structure; with the increase of earthquake and the height of model, the maximal displacement value of beam layer gradually increases; the shock absorption effect of semi-rigid Sun-Mao connection in major earthquake (400gal) is better than that in moderate earthquake (220gal)and minor earthquake (110gal); the seismic amplification coefficient value between layers lies in 1, that between roof and arch shop lies in 0.9 or so.
Abstract: This paper is based on the experiment of Q460 high-strength single-angle equal-leg compression members with a concentric load at one end and normal framing eccentricity at the other end. An experimental program confirmed that the finite element software ANSYS can be used, with a reasonable degree of accuracy, to simulate the experiment and predict the behavior and bearing capacity of single-angle compression members . Then, parametric analysis was done in order to examine the impacts of several factors such as initial bending, Young’s modulus of elasticity and the gusset plate thickness. It was found that initial bending and Young’s modulus of elasticity in the angle section have slight effects on bearing capacity. When the gusset plate thickness to angle width ratio is no more than 0.2, the thickness of plate has less impact on bearing capacity; when the ratio is more than 0.2, the impact increased obviously.
Abstract: Half scaled specimen of steel frame with widen flange connection was manufactured and carried out a pseudo-dynamic experiment. Dynamic characteristics such as the base shear of the steel frame, acceleration response, displacement response of each floor and hysteresis curve were obtained through the TUT control system and data acquisition system. The results show that the acceleration response and displacement response for each floor of the steel frame with widen flange connection tally with actual projects and can well reflect the overall seismic performance of the structure. The steel frame is always in the elastic stage under the earthquake, it has stable hysteretic behavior and good energy dissipation capacity. Reinforced connection improved the seismic performance of the steel frame effectively, and the experimental results can provide reference for the engineering applications.
Abstract: The finite element model was established for the test model of the plate - column -light steel structure according to the application of SAP 2000 and the seismic wave was input in the model , through the analysis of earthquake response, the analysis data of the finite element model was close to the results of the test data,so the finite element model was reasonable.
Abstract: Multiplexing the dynamic vibration absorber (DVA) has tried for improving the vibration absorption efficiency of the dynamic vibration absorber, and because there are several tuning vibration frequencies in the multi-mass dynamic vibration absorber system, the vibration absorption efficiency is more excellent than a conventional single-mass dynamic vibration absorber when they are in the same total mass ratio. In this paper, a two-series-mass dynamic vibration absorber was proposed, optimal parameters of the two-series-mass dynamic vibration absorber have been calculated and vibration absorption is analyzed with the simulation and experiment. The results show that the two-series-mss dynamic vibration absorber can improve vibration absorption, in the same total mass ratio, by about 20% above that of a conventional single-mass dynamic vibration absorber. Based on the above optimal results, the two-series-mass dynamic vibration was used for vibration control on high building, and the practical measure result shows its effectiveness.