Papers by Keyword: Beam Element

Abstract: Building structures around the world have been designed using various framing methods. In Japan, the two-way moment-resisting frame structure, which is designed as a 3D seismic frame with beams connected to the columns, with moment connections in both directions, is traditionally constructed. In contrast, in the United States and many other countries in high seismic regions, the one-way moment-resisting frame structure, which is designed as separate seismic and gravity frame structure with only a few expensive moment connections in seismic frames, is typically constructed. Structures with these different framing systems are likely to exhibit different seismic response and collapse mechanism when subjected to large earthquake excitation. However, the simulation up to complete collapse has almost not been conducted and safety margin to complete collapse of these different framing systems has not been sufficiently understood. In this study, seismic simulation of U.S. and Japanese type three-story steel moment-resisting frame structures is conducted using general-purpose finite element analysis program. Practical macro models used for the simulation are based on beam and shell elements. It is found that composite effects of floor slab accelerate column yielding in both U.S. and Japanese type steel frame structures and drift concentration may occur at relatively small ground motion level and eventually result in complete collapse.

Abstract: In this article, we propose a nonlinear semidefinite program (SDP) for the robust trusstopology design (TTD) problem with beam elements. Starting from the semidefinite formulation ofthe robust TTD problem we derive a stiffness matrix that can model rigid connections between beams.Since the stiffness matrix depends nonlinearly on the cross-sectional areas of the beams, this leads toa nonlinear SDP. We present numerical results using a sequential SDP approach and compare them toresults obtained via a general method for robust PDE-constrained optimization applied to the equationsof linear elasticity. Furthermore, we present two mixed integer semidefinite programs (MISDP), onefor the optimal choice of connecting elements, which is nonlinear, and one for the correspondingproblem with discrete cross-sectional areas.

Abstract: Based on equilibrium equation of beam, the displacement interpolating functions with shear effect of spatial beam elements which are used to simulate the structure members of latticed shells are deduced. The different displacement interpolating functions in compression and tension spatial beam-column elements are unified by the method of Maclaurin series expansion, and the unified expressions which are used to simulate structure members are equivalent to those expressed by stability functions. Numerical analyses results indicate that the second-order elastic analysis method for beam structures proposed in this paper, which can perfectly incarnate the second-order effects and the geometrical nonlinearity of the single-layer cylindrical reticulated shell, is of better accurateness and higher effectiveness.

Abstract: The topic of this paper is the description of different approaches to numerical simulation of prestressed concrete in computational system ANSYS 14.5. Due to increasing popularity of the numerical simulations, the paper aims to divide and describe simple methods and related aspects of modeling prestress on the finite element level. The paper contains three main part: the analytical solution, the numerical solution and the final comparison of the results. The obtained numerical results proved applicability of FEA for solving problems of prestressed concrete elements.

Abstract: 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.

Abstract: According to the standard Specification for Design of Hydraulic Tunnels (DL/T 5195-2004), the free-flow tunnel lining structure should be calculated with beam element of finite element method that based on structural mechanics. However, the practical calculation shows that when the lining structure reaches a certain thickness, the beam element calculation results are no longer accurate. Combining with the engineering example, stress and internal force of lining structure with different thickness were calculated by using beam3 beam element and the solid65 element respectively in frame beam analysis. Differences analysis shows that the solid element is better than beam element in calculation. The influence of solid elements grid size on the result accuracy was conducted, and used to amend the calculation result of the solid element, which provides a certain reference on choosing the right element in the similar projects or structure simulation.

Abstract: Carbon nanotubes (CNTs), one of the important symbol to enter the era of nanotechnology, becomes the most attractive materials with the unique properties, and CNTs shows extensive potential application in drug molecular transmission, CNTs tip and CNTs-based sensors. However, the application of nano-device requires more accurate research about geometric, electronic and mechanical properties which matches to radial breathing vibrational mode in Raman spectroscopy experiment. The shapes and frequencies of radial breathing mode(RBM) and radial breathing-like mode(RBM-like) were investigated by the modified beam element model based on molecular mechanics, and the relationship of frequencies of zigzag and armchair CNTs with length - diameter aspect ratio, diameter and chirality were also discussed respectively. The results show that there are RBM and RBM-like in radial vibration of CNTs, and their frequencies are approximate.

Abstract: To study the behavior changing between cable characteristics and beam characteristics, the geometric shape calculation formulae for tension components with bending stiffness are derived from ones with the boundary conditions of two ends hinged, one hinged joint and the other fixed and two ends fixed respectively. Then, using the concept of tension stiffness, the effects of Cable Characteristic Parameter on the geometric shape of tension components are studied. Analyses indicate that with the increase in the value of the Cable Characteristic Parameter, the cable characteristics of components become more obvious. That is, a bar with enormous tension can be calculated as a cable element even if its bending stiffness is large. In structure finite element analysis, more storage space and computing time could be saved as long as components are simplified with cable elements other than beam elements, the simplification should be carried out basing on the Cable Characteristic Parameter. Calculation results on a hollow beam verify that when tension increases, components’ mechanical properties gradually change from beam characteristics to cable characteristics and eventually they tend to be identical with the theoretical calculation of cable structure.

Abstract: To improve the precision of side impact simulation, MDB model with taper section beam element was established and validated under the GB20071-2006 regulation. The MDB model was used to simulate a side impact test with a production car. The velocities of five key points on the B pillar and the door were outputted and compared with the test data. Numerical results show that the MDB model which based on taper section beam element can meet the requirements of the regulation and is in line with the test data, thus getting a higher accuracy and better simulation application value.

Abstract: In this paper, the development and basic theory of co-rotational finite element method is introduced. The framework of constructing nonlinear element with co-rotational finite element method is proposed. Based on this framework, linear shell and beam element is easy to be extended to nonlinear problem analysis