Limitations in Predicting Human Vibration Response Characteristics From Manikins and Rigid Body Masses

1997 ◽  
Author(s):  
Suzanne D. Smith
2011 ◽  
Vol 117-119 ◽  
pp. 241-246
Author(s):  
Zhen Hai Gao ◽  
Gen Hua Yan ◽  
Peng Liu ◽  
Fa Zhan Chen ◽  
Fei Ming Lv

In this paper we conduct study on flow-induced vibration of large-span upwelling radial steel Gate and its hydraulic hoist. Place an emphasis on vibration response characteristics under two working conditions of diversion and drainage, which proves the safety of hydraulic hoist gate vibration caused by gate vibration. Firstly, we study on dynamic characteristics of fluid-structure interaction of association system of gate and start and stop lever, reveals the discipline of the effect fluid having on structural dynamic characteristics. On this basis, flow-induced vibration characteristics under two conditions of with and without start and stop lever action considered. The results indicate that the gate vibration response with hydraulic hoist used decreases, which explains start and stop lever has certain effect of restraining vibration on gate vibration. In addition, under the working condition of drainage the vibration magnitude of start and stop lever is smaller than that of gate body, which explains there is damping action during transference of gate vibration through start and stop lever. The results find out that on the assumption of optimized gate structure and hydraulic arrangement, it is practicable, safe and reliable to adopt hydraulic hoist. The achievement has directive significance on similar projects construction in the future


2014 ◽  
Vol 940 ◽  
pp. 103-107
Author(s):  
Chang Li Zhao

The probability of frontal collision is the highest in the vehicle collision accidents, and crew injury mechanism of frontal collision is an attractive research subject. Based on the multi-rigid-body dynamics, a “vehicle-crew-belt” dynamics model is introduced, and software Pc-crash is used to simulate dynamic responses of this multi-rigid-body model by referencing basic parameters of FMVSS law. Dynamic response characteristics between the vehicle and the crew body are analyzed so as to expound the link between the vehicle movement and human-body injury. The result shows that a reliable evaluation of frontal collision is achieved, which provides a theory basic and practical reference for the research of accident injury.


Author(s):  
Yasutomo Kaneko ◽  
Kazushi Mori ◽  
Hiroharu Ohyama

This paper presents a simple analysis method for predicting vibration response characteristics of a bladed disk with continuous ring type structure losing a shroud or a shroud and a stab between two blades. This loss introduces a mistuning of the system and the whole bladed disk model must be used to conduct the study. However, the vibration modes change regularly from a sine and a cosine mode, if the bladed disk consists of many blades. By utilizing this phenomenon, the simple formulation of vibration response of a bladed disk can be derived. Second, the parametric study on the vibration response characteristics of a bladed disk losing a shroud or a shroud and a stab is carried out extensively, utilizing the analysis method proposed here. From the calculated results, the vibration response characteristics of a bladed disk are clarified for both of resonant vibration and random vibration. Lastly, the results calculated by the simple analysis method proposed are compared with the results obtained from FEA (Finite Element Analysis) in order to verify the validity of the analysis method.


Author(s):  
Leilei Zhao ◽  
Jian Guo ◽  
Yuewei Yu ◽  
Xiaohan Li ◽  
Changcheng Zhou

The strong vibration responses of the cab system can be restrained by the damper force and the friction of the suspensions for trucks. After the failures of dampers, especially in the case of the complete failure, the anti vibration effect of the friction is prominent. However, the nonlinear vibration response characteristics of the cab subject to the damper complete failure have not been revealed. In order to reveal the nonlinear vibration response characteristics, a dynamic model of the cab system was established and its vibration equations were given. The friction forces existing in the suspensions were determined by the bench test. The influences of the friction forces on the cab vibration under different amplitude harmonic inputs were investigated when the dampers completely fail. The cab vertical displacement changes with the excitation amplitude and the vibration represents various motion states, including the periodic motion, the quasi-periodic motion, and the chaotic motion. The simulation results show that when the dampers fail, the proper friction forces help to suppress the quasi-periodic motion and the chaotic motion of the cab and to reduce the amplitude of the periodic motion. The proper friction forces can make the cab movement far away from the chaos area. They also help to avoid the fatigue damage of the cab floor and suspension parts to improve the service life of the suspension parts and to reduce the maintenance cost of the cab suspensions.


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