Experimental Study on Dynamic Amplification Factor of Simple-Supported Reinforced Concrete Beams Under Impact Loading Generated by an Impulse Hammer
01 Mar 2021-International Journal of Structural Stability and Dynamics (World Scientific Publishing Company)-Vol. 21, Iss: 03, pp 2150036
TL;DR: The empirical formulas of dynamic amplification factor (DAF) specified in current bridge codes only consider the span or fundamental frequency of reinforced concrete (RC) girders in highway as mentioned in this paper.
Abstract: The empirical formulas of dynamic amplification factor (DAF) specified in current bridge codes only consider the span or fundamental frequency of reinforced concrete (RC) girders in highway. Althou...
Citations
More filters
TL;DR: In this paper , a numerical investigation has been carried out to investigate the dynamic response of RC beam subjected to low velocity impact and an attempt has been made to identify and benchmark effects of reinforcement detailing parameters in effective impact resistance of reinforced concrete beams for inclusion in design requirement as per specific performance level.
2 citations
TL;DR: In this paper, a method is proposed to obtain the exact solution for the dynamic analysis of functionally graded porous (FGP) curved beams with general boundary conditions and variable curvatures, and the mode of the mode is described.
Abstract: A method is proposed to obtain the exact solution for the dynamic analysis of functionally graded porous (FGP) curved beams with general boundary conditions and variable curvatures. First, the mode...
1 citations
TL;DR: In this paper , a simplified model that allows the calculation of the displacement and contact force in an impact considering the effect of the force of gravity on the structural response has been proposed, and a coefficient is proposed which enables the evaluation, prior to any analysis, of whether the impact will be significantly influenced by the forces of gravity, whatever the structure under study.
1 citations
TL;DR: In this article , a review of dynamic behaviors of RC structural members is presented using experimental, theoretical, and numerical perspectives, and the available modeling approach and method for incorporating dynamic effects in numerical simulations of RC structures are reviewed.
Abstract: In this paper, research on dynamic behaviors of RC structural members was reviewed using experimental, theoretical and numerical perspectives. First, in a basic overview, measurement methods, main conclusions and current limitations of available dynamic loading tests were presented. Then, theoretical studies on the dynamic constitutive models of RC materials, the dynamic increase factor (DIF) model for concrete and reinforced steel and proposed modified models of dynamic behavior parameters at the structural member level were summarized. Finally, the available modeling approach and method for incorporating dynamic effects in numerical simulations of RC structures were reviewed. Moreover, the work involved a brief introduction to a dynamic hysteretic model established using experimental data, which was designed to provide an alternative approach to the commonly-used DIF method for considering these dynamic effects. This paper, therefore, aimed to provide a valuable reference for experimental studies and numerical simulations on the dynamic behaviors of RC structures—while also putting forward issues that need to be addressed by future work.
References
More filters
TL;DR: The dynamic amplification factor (DAF) is an important parameter in the design of highway bridges and yet no worldwide consensus has been reached so far as to its value as discussed by the authors, and some disagreement exists be...
Abstract: The dynamic amplification factor (DAF) is an important parameter in the design of highway bridges and yet no worldwide consensus has been reached so far as to its value. Some disagreement exists be...
184 citations
TL;DR: In this article, a new set of impact formulas for simple and continuous beams subjected to moving vehicle loads is developed for the deflection, bending moments, and shear forces at the midpoints of simple beams traversed by five-axle trucks.
Abstract: In this paper, a new set of impact formulas are developed for simple and continuous beams subjected to moving vehicle loads. By modeling a vehicle as sprung masses and a bridge structure by beam elements, a parametric study is performed for various simple and continuous beams traversed by five-axle trucks. Central to this study is the adoption of a nondimensional speed parameter s , which is defined as the ratio of the driving frequency of the vehicle, as represented by πv/L, with v denoting the velocity of the vehicle and L the characteristic length of the beam, to the fundamental frequency ω of the beam. From the numerical study, it is concluded that the impact factors for the deflections, bending moments, and shear forces at the midpoints of simple beams are linearly proportional to the speed parameter, and that these formulas can be multiplied by certain modification factors to yield results for continuous beams and support shears. Other parameters studied herein include the vehicle/bridge frequency r...
128 citations
TL;DR: The use of the dynamic impact factor (IM) to account for the impact effect of vehicles has been widely accepted in bridge engineering as discussed by the authors, however, agreement on the evaluation of IMs is yet to be reached.
Abstract: Dynamic impact of moving vehicles on bridges is an important and long-standing issue in the design and evaluation of bridges and has received much attention from researchers and engineers The use of the dynamic impact factor (IM) to account for the impact effect of vehicles has been widely accepted in bridge engineering Accurate evaluation of the IM will lead to safe and economical designs of new bridges and provide valuable information for condition assessment and management of existing bridges Nevertheless, agreement on the evaluation of IMs is yet to be reached Numerous studies have shown that the evaluation of the IM is a difficult task because it is influenced by a large number of parameters and uncertainties As a result, different forms and values of IMs are specified by different bridge design codes and this disagreement has been debated in many studies in the past few decades Furthermore, some field tests observed that the IMs in design codes are overestimated while many other field
107 citations
TL;DR: In this article, a non-stationary random vibration analysis of railway bridges under moving heavy-haul trains by the pseudo-excitation method (PEM) considering the train-track-bridge coupling dynamics is presented.
Abstract: This paper presents a non-stationary random vibration analysis of railway bridges under moving heavy-haul trains by the pseudo-excitation method (PEM) considering the train-track-bridge coupling dynamics. The train and the ballasted track-bridge are modeled by the multibody dynamics and finite element (FE) method, respectively. Based on the linearized wheel-rail interaction model, the equations of motion of the train-ballasted track-bridge coupling system are then derived. Meanwhile, the excitations between the rails and wheels caused by the random track irregularity are transformed into a series of deterministic pseudo-harmonic excitation vectors by the PEM. Then, the random vibration responses of the coupling system are obtained using a step-by-step integration method and the maximum responses are estimated using the 3σ rule for the Gaussian stochastic process. The proposed method is validated by the field measurement data collected from a simply-supported girder bridge (SSB) for heavy-haul trains in China. Finally, the effects of train speed, grade of track irregularity, and train type on the random dynamic behavior of six girder bridges for heavy-haul railways are investigated. The results show that the vertical acceleration and dynamic amplification factor (DAF) of the midspan of the SSB girders are influenced significantly by the train speed and track irregularity. With the increase in the vehicle axle-load, the vertical deflection-to-span ratio (γ) of the girders increases approximately linearly, but the DAF and vertical acceleration fail to show clear trend.
22 citations
TL;DR: In this paper, a mine haul road design technique assumes static tire loads, ignoring dynamic forces, leading to increased road roughness and increased traffic excitations during haulage, generating dynamic loads.
Abstract: Trucks experience excitations during haulage due to road roughness, generating dynamic loads. Current mine haul road design techniques assume static tire loads, ignoring dynamic forces. Thi...
13 citations