Resonant dynamic response and effective static load distributions

2020 ◽  
pp. 155-195
Author(s):  
John D. Holmes ◽  
Seifu A. Bekele
2019 ◽  
Vol 5 (8) ◽  
pp. 1738-1752 ◽  
Author(s):  
Saif Khalil Ibrahim ◽  
Waad A. Zakaria

This paper presents an experimental study on the dynamic response of square footings under effect of dynamic load comes from adjacent footing called the (source of vibration (which is excited by a known vibration source placed on the top of it, the objective is to study the effect of dynamic motion of the source of vibration on a nearby footing, called second footing, both footings rest on collapsible soil (gypseouse soil) with gypseouse content (60%). The study is performed through wide experimental program in dry and soaked condition. The first footing (source vibration) and the second footing have dimensions (80 80 40), (100 100 40) mm respectively and are manufactured from steel, then the two footings placed centrally over soil after prepared it in layers’ form in steel container with (1000 500 500) mm. The first footing exposed to vertical harmonic loading by using a rotating mass type mechanical oscillator to gives a similar effect of the dynamic loads, the second footing loaded with static weight only, under the dynamic excitation. The tests are conducted under dynamic response for three frequencies (10, 20, 30) Hz, the movement (displacement amplitude, velocity, and acceleration) of the second footing studied by varying spacing between the footings. The results showed that the amplitude of displacement, velocity, and acceleration for the second footing decreases when the spacing between footing increase. In addition, the value of these parameters at dry state is greater than its value at soaked state.


1987 ◽  
Vol 109 (4) ◽  
pp. 416-421 ◽  
Author(s):  
Kosuke Nagaya

This paper discusses the dynamic behavior of a flexible multiple disk clutch subjected to dynamic loads. The expressions for obtaining the dynamic response and the transmission torque of the clutch have been derived from the equation of motion of a circular plate by applying the Laplace transform procedure. The results for the clutch subjected to a static load have also been obtained. The comparison between both static and dynamic results has been made to clarify the effect of the impact of the load on the behavior of the clutch.


Author(s):  
Sofia W. Alisjahbana ◽  
Wiratman Wangsadinata

The study of the dynamic response of rigid roadway pavements subjected to dynamic loads such as vehicle loads has received significant attention in recent years, because of the relevance to the design of pavements. This paper presents an analytical solution based on the Modified Bolotin Method to analyze rigid pavements under moving traffic loads. The concrete pavement is modelled as an orthotropic damped plate resting on a continuous elastic foundation, whereby at its edges it is partially fixed. The natural frequencies of the system are computed from a system of two transcendental equations, obtained from the solution of two auxiliary Levy’s type problems. The dynamic vehicle load is expressed as a concentrated load of harmonically varying magnitude, travelling with a variable speed along the rigid pavement. A numerical example is given, demonstrating the applicability of the theory to rigid roadway pavements under actual loading conditions. Therefore, it may be expected that this dynamic load approach may lead to more economic solutions as compared to those obtained from the conventional static load approach.


2013 ◽  
Vol 574 ◽  
pp. 11-19
Author(s):  
Wei Zhao Li ◽  
Xiao Min Huang ◽  
Yan Li

The dynamic response under running vehicle of the bridge includes the static response. The frequency components of simple supported beam dynamic response under the uniform constant force and the harmonic force were discussed. A method using the low pass filter to extract the static displacement from dynamic response curves was proposed and extended to the continuous girder bridge. Simulation analysis describes the process of extracting static displacement. The results show that the method is effective to separate the static and dynamic compositions from the vibration deflection. The dynamic deflection curves of an actual bridge was studied to get the generalized influence lines and then vehicles were laid on them as the static load test program to estimate the static deflection. The results of research show the estimative deflection has high precision and meets the requirements of the bridge inspection. This method can replace the static load test for rapid assessment of the girder bridge.


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