Self-Loosening Effects on Vibration Characteristics of Plates with Bolted Joints: An Experimental and Finite Element Analysis

Measurement ◽  
2021 ◽  
pp. 109922
Author(s):  
Abouzar Pirdayr ◽  
Mehrdad Mohammadi ◽  
Mohammad Javad Kazemzadeh-Parsi ◽  
Majid Rajabi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Vibration Characteristics ◽  
Bolted Joints ◽  
Element Analysis

Fabrication and finite element analysis of vibrating parallel film actuator made with cellulose acetate for potential haptic application

2016 ◽  
Vol 230 (15) ◽  
pp. 2720-2727 ◽  
Author(s):  
Md Mohiuddin ◽  
Asma Akther ◽  
Eun Byul Jo ◽  
Hyun Chan Kim ◽  
Jaehwan Kim
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cellulose Acetate ◽  
Vibration Characteristics ◽  
Experimental Results ◽  
Vibration Velocity ◽  
Frequency Range ◽  
Actuation Frequency ◽  
Element Analysis ◽  
Wide Range

The present study investigates a film actuator made with dielectric cellulose acetate films separated by narrow spacers as a means of electrostatic actuation for potential haptic application. Fabrication process for the actuator is explained along with experiments conducted over a wide frequency range of actuation frequency. A valid finite element simulation of the actuator is made on the quarter section of the actuator by using full 3D finite elements. Vibration characteristics such as fundamental natural frequency, mode shape and output velocity in the frequency range for haptic feeling generation are obtained from the finite element analysis and compared with the experimental results. Experimental results demonstrate that the finite element model is practical and effective enough in predicting the vibration characteristics of the actuator for haptic application. The film actuator shows many promising properties like high transparency, wide range of actuation frequency and high vibration velocity for instance.

Self-Loosening Mechanism of Nuts Due to Lateral Motion of Fastened Plate

2007 ◽  
Author(s):  
Yasumasa Shoji ◽  
Toshiyuki Sawa ◽  
Hiroshi Yamanaka
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Bolted Joints ◽  
Lateral Motion ◽  
Element Analysis ◽  
New Approach ◽  
The Finite Element Analysis ◽  
Mechanical Element ◽  
Vibration Tests

As self-loosening of nuts is really a problem for bolted joints in practical use, countermeasures for the loosening is highly required. In this situation non-loosening fasteners are one of the resolutions for any fastened machinery as an essential mechanical element. Self-loosening of threaded bolt/nut systems has been researched in number of works and most researches were based on experiment and a few were based on the finite element analysis in these years. Using this new approach, various types of nuts can also be examined. Among these nuts eccentric nuts and slit nuts are especially expected to be the solution, as these nuts are reported to endure NAS vibration tests and were not loosened. In the authors’ previous paper, an eccentric nut and a normal nut were analyzed and compared in the aspect of loosening property. In this paper degree of loosening of various nuts was investigated by experiment and the FEA.

Evaluation of Vibration Characteristics for Reactor Coolant Pump Considering Fluid Flow Effect

2014 ◽  
Author(s):  
Ik Joong Kim ◽  
Min Chul Kim ◽  
Gyu Ho Jang ◽  
Dae Hee Jeong ◽  
Oak Sug Kim ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fluid Flow ◽  
Response Spectrum ◽  
Vibration Characteristics ◽  
Working Fluid ◽  
Element Analysis ◽  
Coolant Pump ◽  
Flow Effect ◽  
Unbalance Response

Reactor coolant pump (RCP) is designed for the heat transfer of heat which is generated from reactor vessel to steam generators by circulating the coolant water. RCP is the only rotating equipment in the nuclear steam supply system (NSSS). Therefore, the problem of vibration has arisen caused by the hydraulic forces of the working fluid. These forces can drastically alter the critical speeds and stability characteristics and can act as significant destabilizing forces. So, vibration evaluation of RCP has been considered as a very important issue [1]. Among them, unbalance response caused by weight of unbalancing of rotating shaft could have serious effects on the entire rotor system. Thus, precise unbalance response spectrum analyses are required. In general, in order to evaluate the unbalance response characteristics for centrifugal pump, finite element analysis was performed according to the ISO 1940-1 standard. However, finite element analysis according to the ISO 1940-1 standard does not considering fluid flow effect. So, finite element analysis result and experimental results may be some differences. Vibration characteristics of RCP has affected by fluid flow effect induced from working fluid. Therefore, in order to understand vibration characteristics for the RCP shaft assembly considered in actual operating condition, rotor dynamic analysis should be performed considering the fluid flow effect. In this research, owing to accurately evaluate the vibration characteristics for the RCP considering hydro forces due to the fluid flow, we measured the bearing force and moment take into account the fluid-induced force. And then response spectrum analysis of RCP shaft assembly was performed considering fluid induced bearing radial forces which are measured values. Lastly, evaluate the vibration characteristics considering effect of fluid flow according to the number of revolution.

Load Transfer Analysis of Cracked Bolted Joints

2010 ◽  
Vol 118-120 ◽  
pp. 147-150
Author(s):  
Da Zhao Yu ◽  
Yue Liang Chen ◽  
Yong Gao ◽  
Wen Lin Liu ◽  
Zhong Hu Jia
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Load Transfer ◽  
Three Dimensional ◽  
Element Model ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Three-dimensional finite element model of a cracked bolted joint has been developed in the non-linear finite element code MSC.Marc and attempts were made to validate it by comparing results with those of experiments and other finite element. Issues in modeling the contact between the joint parts, which affect the accuracy and efficiency of the model, were presented. Experimental measurements of load transfer were compared with results from finite element analysis. The results show that three-dimensional finite element model of cracked bolted joint can produce results in close agreement with experiment. Three-dimensional effects such as bolt titling, seconding and through-thickness variations in stress and strain are well represented by such models. Three-dimensional finite element analysis was also used to study the effects of hole mod and crack on the load transfer behaviour of single lap bolted joints. The results show that hole mode has big effect on load transfer of cracked bolted joint. In the whole progress of crack growth, the load transfer through bolt 1 decrease, and almost all of the load duduction of bolt 1 transfer into blot 2 rather than into bolt 3.

Discussions on Behavior of Bolted Joints in Tension

2004 ◽  
Vol 127 (3) ◽  
pp. 506-510 ◽  
Author(s):  
Ouqi Zhang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Analytical Model ◽  
Bolted Joints ◽  
Axial Stiffness ◽  
Conventional Theory ◽  
Element Analysis ◽  
Stiffness Characteristics ◽  
Plate Connections ◽  
Made In

It is known that the behavior of real axisymmetric bolted joints in tension is much more complicated than that the conventional theory describes. Phenomenon conflicting with the theory prediction was observed in experimental and finite element analysis [Kwiatkowski, J. K., Winnicki, L. A., and Krzyspiak, A., 1986, “Stress Analysis of Bolted Tensile End Plate Connections,” Rozprawy Inzynierskie Eng. Trans., 34, pp. 113–137; Webjörn, J., 1988, “Die Moderne Schraubenverbindung,” VDI-Z, 130, pp. 76–78; Grosse, I. R., and Mitchell, L. D., 1990, “Nonlinear Axial Stiffness Characteristics of Bolted Joints,” ASME J. Mech. Des., 122, pp. 442–449; Gerbert, G., Bastedt, H., 1993, “Centrically Loaded Bolt Joints,” ASME J. Mech. Des., 115, pp. 701–705]. Recently, a new analytical model of bolted joints was presented [Zhang, O., and Poirier, J. A., 2004, “New Analytical Model for Axisymmetric Bolted Joints,” ASME J. Mech. Des., 126, pp. 721–728], based on which some discussions are further made in this note.

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