Analytical Solution of Composite Curved I-Beam considering Tangential Slip under Uniform Distributed Load

An analytical solution of composite curved I-beam considering the partial interaction in tangential direction under uniform distributed load is obtained. Based on the Vlasov curved beam theory, the global balance condition of the problem has been obtained by means of the principle of virtual work; integrating this by parts, the governing system of differential equations and corresponding boundary conditions have been determined. Analytical expressions for the composite beam considering the partial interaction have been developed. In order to verify the validity and the accuracy of this study, the analytical solutions are presented and compared with other three FEM results using the space beam element and the shell element. The deflection and the tangential slip of the composite curved I-beam are investigated.

Research of Three-Truss Cable-Stayed Bridge Spatial Characteristic

Wuhan Tianxingzhou Yangtze River Rail-cum-Road Bridge is the first four line rail cable-stayed bridge in china, with three-truss cross section. The new structure presents complex load performance, especially the spatial mechanical characteristics, because the bridge supports six lanes and four railway load, inevitably the main truss will produce a great torque, leading to three-truss cross section distortion and warping deformation. Analysis of the whole bridge spatial structures is carried out. The space shear flexible beam grillage model is used for bridge structure simulation, the upper and lower vertical member and the horizontal link simulated with beam element, while the pylon with space beam element, the cable with cable element. Though the calculation of the cable force and stress, the main girders stress, the pylon stress, the displacement of the main girder and the pylon, it can be shown that the space force and displacement keep within the standard requirement.

The Meticulous Analysis of Skew Beam Based on the Space Skew Beam Element Method

When a skew bridge is analyzed, it is difficult to treat skew boundary conditions with general space beam element in single beam calculation of skew beam bridge. The stiffness of skew bridge cannot be simulated efficiently. In order to improve the accuracy of skew bridge, the stiffness matrix of the space skew beam element is derived based on the principle of minimum potential in this paper, this element is suitable for single beam of skew bridge and grillage method. A corresponding program is completed by Visual C++, the calculated results of different finite element models are compared, so the validity of the proposed model in this paper is validated. This paper can provide reference for plane and space calculation of the skew bridge design.

Seismic Response Analysis of the Semi-Floating System of Long Span Cable-Stayed Bridge

According to the seismic performance of cable-stayed bridge with a project example, using finite element analysis method, establishing the space beam element and link element calculation model, the dynamic characteristic and the seismic response of the cable-stayed bridge with selected three earthquake waves were calculated, the results were compared with the of the response spectrum method.The results show that:the semi-floating system of cable-stayed bridge is great flexibility, the vibration cycle is generally longer; the results by using the response spectrum method are smaller; the cable-stayed bridge should be calculated in accordance with the specific circumstances of the project with multiple seismic waves.

Dynamic Stability Analysis of Steel-Concrete Composite Ribbed Shell under Vertical Step Loads

The steel-concrete composite ribbed shell is a kind of novel space structure. In this paper, using space beam element and shell element, based on the nonlinear FE theory, considering the elastic-plastic material and geometric nonlinear, in view of the system dynamic response of identifying method, dynamic stability of steel-concrete composite ribbed shell under vertical step loads are studied. Setting up the relationship, it is between load amplitude and dynamic response of the structures, comparing rigid joint with hinge joint on the edge of structure, Critical load conditions of dynamic stability are defined.

Mechanical Analysis of Fracturing String with Double Packers in Horizontal Well

The design and mechanical analysis of fracturing string was one of the key technical problems in fracturing operation. Considering contact friction and curvature effect, contact nonlinear problem of fracturing string was solved by space beam element and multidirectional contact gap element method. Contact state, contact reaction force and corresponding frictional resistance between the fracturing string and borehole or inside casing wall could be accurately described by gap element, which generated less simplification in the mechanical model and more precise calculation of force and deformation. The calculations of field examples has shown that while the distance is 10 m, 20 m or 30 m between two packers of fracturing string, maximum axial sliding displacement of the first packer is 0.19 mm and sliding displacement of the second packer is 11.17mm, 23.78mm , or 36.46 mm. The theory basis is provided for the decision of reasonable distance between two packers.

Influence Analysis of Mortar Elastic Modulus to CRTS III Slab Track Vertical Dynamic Response

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.

Derivation of Geometrieal Nonlinear Stiffness Matrix for Space Beam Element

A space beam element is derived for geometrically nonlinear analysis based on the principle of minimum potential energy principle. The impact of high-order nonlinear is considered by introducing the axial deformation into the stiffness matrix. The large displacement matrix is divided into four and the initial stress matrix into three submatrix

Simulating Research on Rod String’s Gyro Effect Caused by Eccentric Rotation in Circular Tube

Based on the influences of eccentrical rotating inertial centrifugal force and axial force on the rod string’s lateral bending deformation, the finite beam element model of rod string’s bending deformation is established. The constraint to rod string’s bending deflection exerted by inwall of circular tube and the distinction of the constraint to rod string’s deflection because of the different gaps between rod string to circular tube and coupling to circular tube are both taken into account. Meanwhile, removable spring elements with two directions are adopted, by which the non-linear contact problem between the rod string and circular tube is well resolved. Combining space beam element and spring elements with two directions, the corresponding finite element simulating program is also developed. Several simulating results can be shown as follows: eccentric rotation of rod string is able to produce gyro effect in vertical circular tube; The shape of the rod string’s deformation is a spiral which is thin on the upper-part and dense on the under-part; Gyro wave numbers are affected obviously by rotating speed, eccentricity, axial concentrated force, axial distributed force and length of the rod string.