Papers by Keyword: Beam

Abstract: For computation of reaction, internal force and displacement of a beam, the displacement equation from Conversion Method is used in establishing compatibility condition of deformation. In the process of Section-Conversion Method, the joints without sway is set as the coordinate criterion. Cutting the part between two joints as a base element with the method of section, it becomes a simply supported beam in form. The internal forces at the section cut are those which equivalent forces from other side of the beam. According to the axiom of action and reaction, the equivalent forces react to the other part of the beam. The displacement equations are used for all parts one by one. The precision resolutions of reaction, internal force and displacement of a beam are achieved.

Abstract: Under driving force F(x,t)=Q*sinwt, a time-domain DQ (differential quadrature) method for dynamic problems of beams with initial-boundary value conditions is presented in this paper. On the basis of governing partial differential equation, the discrete DQ method adopted both in space domain and time domain in this method gives rise to new differential quadrature linear equations with complete initial-boundary value conditions for solving all parameters of the displacement-field. The numerical examples show that the computational accuracy and efficiency of time-domain DQ method is better than finite element method based on time-domain difference.

Abstract: This paper presents an investigation on the nonlinear dynamic response of piezoelectric beam reinforced with boron nitride nanotubes (BNNTs) under combined electro-thermo-mechanical loadings. By employing nonlinear strain and utilizing piezoelectric theory, the constitutive relations of the piezoelectric beam reinforced with BNNTs are established. Then the dynamic governing equations of the structure are derived through variational principle and resolved by applying the finite difference method. In numerical examples, the effects of geometric nonlinear, voltage etc. on the nonlinear dynamic response of piezoelectric beam reinforced with BNNTs are discussed.

Abstract: In the decoration integration of steel structure, overhead floor achieves a separation of decoration and structure. Overhead floor system is composed of steel bracket, beam and floor. Reasonable overhead floor structure to ensure the safety of the whole structure has important significance. In this paper, the new form of beams named the cold bending cap steel is proposed and the size design of the new beam is made. While maintaining the original beams on the basis of mechanical properties, the new form of beams increase effective use height above the floor. In addition, the construction technology, construction requirements, the error control of overhead floor system, etc. are summarized and some author's suggestions in terms of modular are made.

Abstract: This article briefly analyzes the European norms EN 1992-1-1 design of concrete provisions , oblique shear capacity force section of concrete beams without stirrups calculation method, the factors affecting beams without stirrups carrying capacity, such as longitudinal reinforcement ratio, shear span ratio , concrete strength , compared to the Central European norms consider different ways . Through comparative analysis, some differences between China and the EU to get concrete oblique section design methods , but also pointed out the Chinese norms factors longitudinal reinforcement ratio is not considered.

Abstract: A finite element (FE) model for externally bonded FRP (EB-FRP) strengthened RC beams is developed to simulate the responses of the structural system, to gain a better insight into the mechanism of the system. Comparisons between the predictions of the model and test results are presented to demonstrate its capability and accuracy.

Abstract: Based on the two-dimensional theory of elasticity, Hamiltonian system is introduced to solve the bending of orthotropic beams and the original problems come down to solve the eigensolutions of zero eigenvalue. The symplectic concept makes no hypothesis of deformation along the thickness direction. Thus, the current method can precisely analyze beams with arbitrary depth-to-length ratio, and can deal with arbitrary end conditions. In additional, a new improved boundary conditions for fixed ends beam is presented. Numerical examples showing comparison with other methods are given to illustrate the accuracy of the present approach.

Abstract: Structural vibration is undesirable, wasting energy and possibly leading to excessive deflections and structure and machine’s failure. In order to reduce structural vibration, one of the common way is considering vibration absorber system attach to the structure. In this study, a vibration absorber is developed in a small scale size. The host structure selected for the study is a fixed-fixed ends beam. The effectiveness of vibration absorbers attached to a beam is investigated through experimental study. In prior to experiment, a finite element analysis of Solidworks® and analytical equations of Matlab® are produced in order to determine the structural dynamic response of the beam, such as the natural frequency and mode shapes. The preliminary results of finite element analysis demonstrate that the first five natural frequency of fixed-fixed end beam are 17Hz, 46Hz, 90Hz, 149Hz and 224Hz, and these results are in agreement with the beam’s analytical equations. However, there are slight discrepancies in experiment result due to noise and error occurred during the setup. In the later stage, the experimental works of beam are performed with attached vibration absorber. Result shows that the attachment of vibration absorber produces better outcome, which is about 45% vibration reduction. It is expected that by adding more vibration absorber to the structure, the vibration attenuation can significant.

Abstract: Although fundamental, vibration of a cantilevered Euler-Bernoulli beam with spring attached at the tip is not found in literatures and is here solved analytically and numerically using finite element approach. The equation of motion of the beam is obtained by using Hamilton’s principle. Finite element method is utilized to write in-house program for the free vibration of the beam. Results show plausible agreements.

Abstract: This paper presents numerical solutions of straight plane beam structures rested on an elastic (Winkler's) foundation. It is a continuation of our previous work (see Part 1 of this article) focused on practical applications and solutions including nonlinearities in the foundation (i.e. bilateral linear, bilateral linear + cubic, bilateral linear + cubic + quintic approximations and unilateral approximation for dependencies of reaction forces on deflection in the foundation). For solutions of nonlinear problems of mechanics (i.e. differential 4^th-order equations), the Finite Difference Method (i.e. the Central Difference Method) is applied in combination with the Newton (Newton–Raphson) Method. Finally, in one example, linear and nonlinear approaches are solved, evaluated and compared. In some cases, there are evident major differences between the linear and nonlinear solutions.