Papers by Keyword: Beam

Abstract: Comb accelerometer structure includes mobile fingers connected with proof mass and fixed fingers linked with anchor. Under a huge shock, the reliability analysis of the accelerometer is reduced to the one of simple beam due to the stopper, i.e. shock response of double-clamped beam and single-clamped cantilever. From the quantitative analysis and numerical simulation in this paper, some useful conclusions are obtained: first damage or fracture for comb accelerometer is the finger beam rather than the bearing beam.

Abstract: In this paper the transverse vibration of a fixed-fixed end beam will be investigated by experimental measurement. This paper is concerned with the classical theory formula as well as the analysis and design of the dynamic vibration absorber (DVA) which is composed by a flexible beam with two masses symmetrically mounted at its both sides. The fixed end beam clamped to a static structure where dynamic vibration absorber then being attached onto it. One side of end of the beam is harmonically excited in transversal direction by an electric shaker. The structure equipped with accelerometer sensor to measure its vibration response amplitudes and natural frequencies. The dynamic vibration absorber arrangement located under motor near the beam end was then being vibrated and done in two conditions; before and after mounting dynamic vibration absorber. The comparison amplitudes before and after equipped dynamic vibration absorber were compared and discussed. From the experimental results, proved that the DVA has successfully absorbed the beam vibration hence reduced the vibration amplitude of the beam structure. The knowledge and result obtained from this study can help engineers control the vibration level of beam structure.

Abstract: This paper presents an experimental investigation and a numerical analysis on the bending strength and behavior of cold-formed steel C-section and ∑-section beams with complex edge stiffeners and web holes. Local buckling, distortional buckling and interaction between local and distortional buckling were observed in the tests. The experimental results show that the stiffened web has great influence on member's bending strength. Compared with C-section specimens, the stiffness of the web stiffeners of ∑-section specimens reduced the influence of the holes. The finite element analysis results show good agreement with the experimental results in terms of bending strength and buckling mode.

Abstract: Shear strength and stiffness of fire-damaged reinforced concrete (RC) beams were researched. The nonlinear finite element method (FEM) was developed to simulate shear strength of fire-damaged RC beams. Considering mechanical properties deterioration of concrete and steel reinforcing bar, the parameters of fire-damaged RC beams, including fire exposure time, shear span to depth ratios, concrete strength, diameters of stirrups and spacing of stirrups, were analyzed. Based on numerical analysis, the change of shear strength and stiffness of fire-damaged RC beams were identified. The results showed that shear strength and stiffness of fire-damaged RC beams changed under different parameters. With increase of fire exposure time or increase of shear span to depth ratio or decrease of concrete strength, shear strength and stiffness of fire-damaged RC beams descended obviously. With decrease of diameters of stirrups or increase of spacing of stirrups, shear strength of fire-damaged RC beams descended gradually, but stiffness of fire-damaged RC beams had little change.

Abstract: The aim of this paper is to create a method for reduction of constructive weights of system of cross-beams (grillages) optimizing its elements. The study has practical application and aimed primarily to companies who design civil and industrial buildings, different types of mechanical constructions, vehicle industry, etc.

Abstract: Reinforced concrete is a common structure in buildings in Taiwan. Steel bars, concrete materials and the structural strength of the reinforced concrete deteriorate due to high temperature deriving from a fire. Therefore, it is essential to assess its structural safety and analyze whether the architectural structure will remain its design strength undergoing a fire. This study employs Fire Dynamics Simulation (FDS), fire simulation software, to construct model of thermal flow field. By integrating FDS with PHOENICS, thermal flow software, this study also calculates the effect of the fire’s thermal transmission on the building, investigates the effect of the fire size and the mode the beam undergoing a fire on change of the structural strength, and provides quantified data for safety assessment for buildings which have undergone fires.

Abstract: Damage-induced local response is probably easy to be captured by the higher modes of the structures, especially for the small defects. The aim of this paper is to overcome the inherent deficiency of fractal dimension to identify crack when implemented to higher mode shapes. The proposed approach reconstructs the higher mode shape through rotation transformation, and then the fractal dimension analysis is implemented on this new mode shape to yield a fractal dimension trajectory. The location of the crack can be determined by the sudden peaks at the fractal dimension trajectory. The applicability and effectiveness of the proposed method is validated by using numerical simulations on damage identification of a cracked cantilever beam.

Abstract: It is very important to draw internal forces diagram(shear diagram, bending moment diagram)of beam quickly and accurately for students. Only hold its regular and can use proficiently, we can laid a solid foundation for the study of specialized course .This article mainly based on the characteristics of the beam, analyzed shape and laws of the internal forces diagram and summary of the methods ----"pithy formula law"

Abstract: This paper presents a new time-domain DQ (differential quadrature) method for structural vibration analysis. It adopts differential quadrature method both in space domain and in time domain on the basis of governing partial differential equation and initial-boundary value condition of vibration problems of structures, and gets new differential quadrature linear equations with complete initial-boundary value conditions for solving all parameters of the displacement-field. The examples in this paper show the time-domain differential quadrature method is a useful and efficient tool for structural vibration analysis.

Abstract: An analytic model is developed to obtain the dynamic response of beams with initial velocities of the upper beam which is clamped at both ends and fully supported by metal foam, as a representative arrangement for protective structures. In large deflection, plastic bending and stretching in deforming regions are considered and the membrane factor method is introduced in the model to take into account the effect of axial force in the yielding. The relationships between the final displacement of the center in the beam and the dimensionless parameters are obtained. This model can predict the dynamic effects of different initial velocities and beams with different lengths, thickness and yield strength of cores.