scholarly journals The effect of rotatory inertia on natural frequency of cracked and stepped nanobeam

2020 ◽  
Vol 2 (3) ◽  
pp. 035009
Author(s):  
Mainul Hossain ◽  
Jaan Lellep
1969 ◽  
Vol 91 (4) ◽  
pp. 925-930 ◽  
Author(s):  
P. G. Kessel ◽  
A. L. Schlack

A theoretical analysis is presented on the damped steady state response of a simply supported beam on an elastic foundation subjected to a cyclic moving load that oscillates longitudinally along the beam about a fixed point. Loadings of this type have been recently shown to yield an infinite number of load movement frequencies that will excite resonance of a given natural frequency of an elastic member or system of members. It is the purpose of this investigation to introduce damping into the problem in order to determine both the absolute and relative importance of this infinite number of load movement frequencies that will excite a given natural frequency of a beam. The mathematical analogy between the problem of a beam resting on an elastic foundation and that of a long circular cylindrical shell with axial and rotatory inertia neglected is noted. Hence the results obtained are applicable to either problem. Numerical results are presented to illustrate the effects of damping, frequency of oscillation of load movement and amplitude of load movement on the dynamic deflection of the beam.


2020 ◽  
Vol 15 (1) ◽  
pp. 37-44
Author(s):  
El Mehdi Echebba ◽  
Hasnae Boubel ◽  
Oumnia Elmrabet ◽  
Mohamed Rougui

Abstract In this paper, an evaluation was tried for the impact of structural design on structural response. Several situations are foreseen as the possibilities of changing the distribution of the structural elements (sails, columns, etc.), the width of the structure and the number of floors indicates the adapted type of bracing for a given structure by referring only to its Geometric dimensions. This was done by studying the effect of the technical design of the building on the natural frequency of the structure with the study of the influence of the distribution of the structural elements on the seismic response of the building, taking into account of the requirements of the Moroccan earthquake regulations 2000/2011 and using the ANSYS APDL and Robot Structural Analysis software.


Author(s):  
Masanori MATSUSHITA ◽  
Nobukatsu OKUIZUMI ◽  
Yasutaka SATOU ◽  
Osamu MORI ◽  
Takashi IWASA ◽  
...  

2019 ◽  
Vol 132 ◽  
pp. 335-352 ◽  
Author(s):  
Ganggang Sha ◽  
Maciej Radzieński ◽  
Maosen Cao ◽  
Wiesław Ostachowicz

Author(s):  
U Neureder

Many studies of mechanisms contributing to steering wheel nibble have been carried out in the past. This paper deals with some aspects that have not yet been studied, or those that have been presented by several authors but are deemed to be controversial. Firstly, an overview of stimulation sources (disturbance factors), and the significance these have with respect to steering nibble, is given. As an example of the controversial aspects of the problem, this paper deals with the assumption of dry friction in steering gear models and its conflict with the observed transfer of vibration caused by small (realistic) amounts of imbalance or tyre force variation. After modelling the steering gear resistance correctly, it is possible to identify, in the steering gear, a natural frequency that contributes reasonably to the nibble phenomenon. Based on this new model, a CAE study on parameter sensitivity, using the ‘design of experiments’ approach, is presented.


Robotica ◽  
2021 ◽  
pp. 1-15
Author(s):  
Xiaochu Liu ◽  
Yunfei Cai ◽  
Weitian Liu ◽  
Linlong Zhang ◽  
Chengxin Hu

Abstract In this paper, a special 6-PUS parallel manipulator (PM) is utilized as a shaking table. Unlike the existing results about 6-PUS PMs, we make the actuator direction collinear with the linkage direction at neutral position. With respect to the application background, a further analysis of the special PM is carried out from the perspective of motion/force transmissibility, natural frequency and acceleration capability. Specially, the complete dynamics model is established based on the Kane method. Then, generalized transmission indices based on the screw theory are utilized to reflect its motion ability, and a model of natural frequency is proposed with the axial stiffness of linkages considered. Finally, the effect of the angle between the actuator direction and the linkage direction α on various performances is analyzed, and other results are included to illustrate its feasibility and usability.


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