Papers by Keyword: Ultimate Capacity

Abstract: The present paper suggests an on-line hybrid test environment for evaluating the seismic performance of steel bracing connections. The test method combines substructuring techniques and finite element analysis. The behavior of the brace member is simulated by the finite element analysis program ABAQUS, while the bracing end connections are physically tested. Two actuators are used to simulate the physical continuity between the analytical and experimental substructures by controlling axial load and out-of-plane rotation. A MATLAB user subroutine is created as the interface between the main control program and ABAQUS to impose the target rotation and axial force to the connection quasi-statically. A gusset plate connection designed to behave as a pin connection is tested and its efficiency to accommodate inelastic rotations up to a 4.0% story drift is evaluated. The test method is reasonable and smooth operation is achieved. The test system ensures pragmatic loading and boundary conditions to the brace connections, which are tested in full interaction with the brace member until failure. The maximum strength and rotation capacity of the connection can be clarified under actual cyclic inelastic rotations and varying axial loads derived from the inelastic behavior of the brace member.

Abstract: In order to improve the ultimate capacity of pressure hull, a new method to improve the external bearing limit is put forward and residual stress is used. Based on the lame formula, the bilinear hardening model is considered to deduce the residual stress formula. Two influence parameters are analyzed by theoretical and numerical methods. The accordance of results shows that the accuracy of theoretical derivation can be verified by FEM. The 3D models with residual stress or not are built in ABAQUS. According to a lot of data of simulation experiments, the result indicates that the directional residual stress is useful, especially compressive on the outer surface of the pipe and the hoop stress keeps tensile on the inside surface. This kind of stress distribution is helpful to the cylinder structure and can improve its ultimate capacity of external pressure. Thus, the formula considering hardening material can guide the full plastic bulging to produce the desired stress distribution.

Abstract: For the problem of square concrete-filled steel tube (CFST) under the action of axial pressure, concrete received local compression and buckling occurred in the application of thin-walled steel pipe.Using built-in spiral reinforcement to strengthen the constraints of thin-walled square steel tube to core concrete. And by using ANSYS program established the built-in spiral reinforcement of thin-walled square steel tube concrete composite column 3 d finite element model, and the results show that spiral reinforcement strengthen the constraint effect, increase the ultimate bearing capacity of the composite columns of square steel tube by 7.41%; And with stiffening rib and rod measures were compared, built-in spiral ripe construction is convenient, easily applied.

Abstract: The diamond bird-beak XX-joint is a novel configuration for tubular structures and there are few correlated papers for it. Non-linear FE analyses are carried out on axially loaded XX-joints in order to study the mechanical properties of this type of joint. The individual influence of the following geometric parameters on the joint capacity, brace to chord width ratio β, chord width to wall thickness ratio 2γ, and brace to chord thickness ratio τ is made clear. Increasing either β or τ will increase the joint capacity and increasing 2γ will decreases joint capacity. The out-of-plane braces tension always decreases the ultimate capacity of joint and the equal tension and compression in the chord member have the same influence on the joint capacity. A reduction equation is proposed to consider the load effect of chord and out-of-plane braces axial forces.

Abstract: A calculation model about failure mode and ultimate bearing capacity of steel truss coupling beam is proposed based on compatible distortion and balance conditions, second-order effect, elastic-perfectly plasticity and strain state about eight specimens when these specimens fail under low cyclic reversed loading. And then this model is applied to analyzing influences of height, span and chord stiffness on bearing capacity of truss. Some valuable results are obtained such as advantageous range of span-to-height ratio and influence laws of chord stiffness on ultimate capacity.

Abstract: As a newly developed type of foundation for deep water offshore and marine engineering, the suction caisson is usually subjected to combined loading of vertically uplift load, horizontal load and moment. Performance evaluation and design theory for such a new type of foundation can not meet the basic requirements of engineering practice sufficiently at present. In this paper, the general-purpose finite element analysis package ABAQUS is employed to conduct three-dimensional numerical analyses on load-carrying features of suction caisson foundation. Then the ultimate bearing capacity of suction caisson foundation under monotonic load for two drainage conditions of the soil is evaluated by displacing-controlling procedure.

Abstract: In this paper，the ultimate bearing capacity of unstifened overlapped CHS K-joints is investigated by using the finite element method with influence of weld and non-weld on joint ultimate capacity under brace different bearing capacity. with angle of chord and brace is increasing ultimate capacity to lowed more and more small，which hidden weld is non-weld by one brace is pulled and other is pressured. ultimate capacity no influence to hidden welded and non-welded by both brace is pulled.

Abstract: Abstract. The diamond bird-beak TX-joint is a novel configuration for tubular structures and there are few correlated papers for it. Non-linear FE analysis is carried out on axially loaded TX-joints in order to study the local static behavior of this type of joint. The individual influence of the following geometric parameters on the joint capacity, section width ratio β of brace to chord members, section width to wall thickness ratio 2γ of chord member, and wall thickness ratio τ of brace to chord members is made clear. Increasing either β or τ will enhance the joint capacity and increasing 2γ will lower joint capacity. A reduction equation is proposed to consider the load effect of chord and the axial forces of out-of-plane braces. The tension of out-of-plane braces always lowers the ultimate capacity of joint. The same tension and compression have the equal influence on the joint capacity.

Abstract: Bridge decks in composite bridges endure local vehicle load directly and failure is apt to occur in bridge decks, so the decks in Jiubao Bridge were designed to be renewable components. Space finite element model of Jiubao Bridge was established. Stress variation of upper and lower edge of the girder under dead load was analyzed when each deck changed locally. Stress variation processes of various whole span replacement plans had been analyzed and the stress envelope was obtained. The calculation results show that local bridge deck replacement has no obvious influence on the steel girder stress. While the plan that remove bridge decks from mid-span to arch foot has less influence on the girder stress compared to other whole span replacement plan.

Abstract: A finite element model simulating the experiment on multiplanar unstiffened CHS KT joints with K-plane overlapped and out-of-plane not (KT-IPOv joints), with the background of Suzhou International Convention & Exhibition Center, was advanced and validated by comparing failure mode and the ultimate capacity with experimental results, which is shown to be in good agreement with the test result. Using this model, the effect of non-dimensional parameters on ultimate capacity of KT-IPOv joints were studied, and resistance comparison between multiplanar KT-IPOv joints and uniplanar overlapped K-joints was carried out. The results of FE parametric Analysis conclude that multiplanar parameter ζ _t, τT and βT have not significant influence on the ultimate strength; the effect of non-dimensional parameter β_K, τK, γ, Ov on the resistance of multiplanar KT-IPOv joints has the same as that of uniplanar overlapped K-joints; the strength of multiplanar KT-IPOv joints have been not significantly influenced by the configuration with the brace inside T-plane which it is not subjected to force; it is suitable and feasiable that ultimate capacities of KT-IPOv joints predicted by formula of uniplanar K-joints.