Advanced Materials Research Vols. 163-167

Abstract: On the basis of the Generalized Beam Theory (GBT), this paper presents an elastic analysis of the distortional critical stress of cold-formed thin-walled lipped channels in combined compression and minor axis bending. The results obtained using the exact analysis presented herein have shown excellent agreement with previous available results. And the accuracy, validity and effectiveness of the presented solution were demonstrated. The calculating process was displayed by an example which can give reference to the research and design. This paper will contribute to the understanding of distortional mechanics in thin-walled members.

Abstract: Tianxingzhou cable-stayed bridge firstly adopts the innovative structure which is composed of three main trusses and three cable planes, and its mechanical properties are different from those of the traditional structure with double main trusses and double main planes. In this paper, based on the study about the cable tension distributed properties of the completed bridge with three cable planes, and through comparing analysis on the bridge with three main trusses and that with double main trusses, the mechanical properties of the bridge with three main trusses and three main planes were investigated. In the end, the calculated results show as follows: cable tension distributes well after rational optimal calculation. Although there will be more construction works for the added cable plane, per cable tension reduces, and it makes the anchor zone with simpler structure and cable replacing more conveniently; Under same level stress, the three-main-truss structure has smaller component, which makes construction more conveniently; The three-main-truss structure has a lower torsional stiffness, but it can be effectively improved by enhancing axial rigidity of lateral bracing; Under the condition of the same materials, the bridge with three main trusses has lower stress. Therefore, the cable-stayed bridge with three main trusses and three main planes is the rational choice for multi-line railway and rail-cum-road bridges.

Abstract: In order to study the influence of expansive agent on the performance of CFST column with the creep due to dead load of the practical construction, in this paper, based on the simulation phase of construction, a series of experiments were conducted to study effect of the expansive agent dosage on the ultimate bearing capacity of CFST columns and the creep deformation in the longitudinal direction. Also the experiments were completed to comparative study on the problem of the recycled aggregate concrete -filled steel tube (RACFST) column. It is found that the ultimate bearing capacity of the CFST column is increased a lot when using the expansive agent, while for the RACFST column it has just a little increase. In contrast, for the RACFST column, there is a greatly increase on the creep deformation in the longitudinal direction, and the more expansive agent dosage the larger deformation, but it is not so obvious effect for general CFST column.

Abstract: Aggregate is the main contribution to shield the radiation in the radiation shielding concrete. Based on the fact that the heavy element barium has excellent γ-rays shielding function, sludge with the high content of barium has been made into aggregate with low dissolution rate and high strength by calcination at high temperature; the existing forms of element barium after it was melted inside the aggregate have been analyzed by using XRD and SEM techniques; the linear attenuation coefficients have been measured among the functional aggregates, basalt and barite. The results have showed that the radiation shielding capacity of functional aggregate has been improved substantially compared with the basalt, however, it is equal to barite.

Abstract: In order to study the friction contact effect between cable and membrane in cable-membrane structures, a tensioned cable-membrane FE model which has a stable cable (valley cable) is created with FEA software ANSYS. The friction contact between the valley cable and membrane surface is simulated by contact elements in ANSYS, and the effect of friction contact surface is considered by the introduction of friction coefficients. Three different design valley cable forces (15kN, 20kN and 25kN) are considered in form-finding and static analysis, and valley cable force losses are analyzed. Results show that valley cable force loss due to friction contact should be considered obviously when design valley cable force is relatively small.

Abstract: The paper is based on the relatively large-span, thin thickness of the arched corrugated metal roof (ACMR) and the fact that the structure would suffer asymmetry swinging within the vertical plane and structure vibration under the effect of the wind and earthquake. A structure strengthening method called the arched corrugated metal roof with ring hoops (ACMRH) is adopted. With SAP2000, a finite element model is established, with type of w666-18m span, rise-span ratio 0.25, 1mm of thickness and condition of fixed support as its research object. The dynamic time history response is analyzed and compared with documents [1]. Result is shown as below. With the same earthquake wave on the structure added, the vertical and horizontal deflection displacement of the most unfavorable point of the arched corrugated metal roof with ring hoops is always less than that of the structure without ring hoops. The maximal decrement is about 28%. This result indicates the arched corrugated metal roof with ring hoops has a better effect on controlling the displacement deformation.

Abstract: To analysis progressive collapse behavior of single-layer reticulated shell under severe earthquake, based on spatial fiber beam element failure criteria, a simulation method on progressive collapse of shell is presented, which account of mechanical properties of components after buckling and damage accumulation effect of combine hardening material. And a computation program is developed correspondingly. At last the method and program proves to be applicable by an example.

Abstract: T-struts subject to centroid compression buckle flexural-torsionally about their axis of symmetry. When the force is applied at the shear center of the section, T-struts buckle either flexurally or torsionally without coupling of flexure with twisting. Although the buckling load of shear center loading is greater than that of centroid loading, i.e. T-struts in elastic stage provide larger resistance to buckling about their axis of symmetry when the compression is applied at the shear center in lieu of the centroid of the section, T-struts with defect such as fabrication error, load eccentricity and residual stress always buckles in the elastic-plastic range actually, and the design capacity decrease by shifting the working line of a T-section compression chord to the shear center. That peculiarity is verified by the nonlinear buckling analysis of T-struts models in ANSYS.

Abstract: Singapore Cool Dry conservatory is a huge space steel structure which is for exhibiting plants suited for living in cool and dry conditions. Due to its seashell shape, it adopts arch-shell hybrid structural system. Double-layer glass curtain walls are suspended to the shell, while cables are tensioned between large arches to increase lateral stability capacity. Because of this structure’s specialty, traditional structural design software in China can not meet the need. FEA software ANSYS was employed to make design optimization, and make further verification. The global stability bearing capacities considering geometry non-linear elasticity and elasto-plasticity conditions were evacuated and analyzed.

Abstract: In order to further understand the seismic behavior of connections to concrete-filled square steel tubular columns with three edges welded interior diaphragm, basic sample and corresponding finite element models are constructed and analyzed according to criterion; furthermore influences on seismic behavior of such connections from many factors such as axial load ratio, height of steel beam, strength of steel beam and interior diaphragm and so on are studied. Results show that the base sample has excellent seismic behavior; such factors as axial load ratio, height of steel beam, strength of steel beam and interior diaphragm have great influence on seismic behavior. Therefore, the feasibility of such connections at edge columns and corner columns is further validated.