Papers by Keyword: Dynamic Force

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Authors: X.S. Li, It Meng Low
Authors: Xiao Hong Yue, Yong Jian Mao, Hao Pu, Bao Liang Niu, Lei Wang, Song Wang, Dai Rong Wu, Yi Yu
Abstract: The technique of centrifuge model test has been widely used in geotechnical mechanics and engineering because of its low cost and low test scale. In order to investigate the dynamic behaviors of the geotechnical model under explosion, we are developing an explosion geotechnical centrifuge. The dynamic environment of explosion is necessary to be determined for the strength design of the centrifuge nacelle. This paper presents the dynamic force measurement of the model container to the centrifuge nacelle under a typical explosion. Firstly, three cylindrical supports were designed and calibrated by quasi-static compressive tests. The force-strain relations are measured and linearly fitted. Secondly, an explosion test was performed and the dynamic strain histories of the supports were measured. Then the dynamic force histories were obtained combined with the calibration results. The investigation provides an understanding of the dynamic environment for the centrifuge nacelle design.
Authors: Peter Sivák, Oskar Ostertag
Abstract: This paper presents the results of the investigation of the causes of the occurrence and the influence of the dynamic effects in the couplers of the remotely controlled electric shunting locomotives and a set of fully loaded rail cars. These are typical rail-road sets, working at the logistic area of the central ore trans-shipment of large steelworks with heavy rail traffic. The stated effects lead to excessive deterioration of the supporting structure of the locomotives, axle gripping, drive mechanisms and braking systems. To achieve the desired goal, the methods and means of numerical and experimental modelling have been used. Based on the performed numerical and experimental analyses were then specified the recommended design and operational measures to prevent the failures mentioned above.
Authors: Cheng Zhong Zhang, Bang Yan Ye, Li Dong Liang, Xiong Jia, Guang Ming Zhang
Abstract: A violin bridge kept in place by the pressure of the four strings has a powerful effect on the tone of the instrument. Its dynamic mechanical behaviors are investigated using finite elemental modeling and experiments in this paper. Modal and frequency response analysis of an isolated bridge are carried out. Numerical results show that the frequency responses are related to the vibration modes of the bridge. Particularly, the bridge hill is due to the bridge itself, and linked to the in-plane rocking mode of the bridge near the bridge hill peak. Three-dimensional dynamic forces exerted to the violin plates by the strings and bridge are then experimentally measured using a dynamometer. The experimental results are then analyzed and correlated to the simulation. The frequency response analysis of an isolated bridge is demonstrated to be a potential tool to study the mechanical behaviors of the violin bridge.
Authors: L. Castro, P. Viéville, Paul Lipiński
Abstract: This paper proposes an experimental method for obtaining the Frequency Response Function (FRF) between a dynamic force and the signals emitted by a piezoelectric dynamometer. This function is known as Transmissibility. In the FRF obtaining stage, different configurations of mounting and excitation have been compared to improve the function quality. The method has been developed with a three components dynamometer fixed on a milling machine. The FRF has two principal applications: it is used to evaluate the measurement system accuracy and to correct the measurements, if necessary. The method has been developed with the purpose of studying the cutting forces in machining process. Furthermore, it has been identified the influence of the parts of the measurement chain in the measuring system response.
Authors: Xiao Yan Zhang, Xu Chao Liu, Shun Qun Yang, Li Li Dong
Abstract: Due to the larger workflow, more complex foundation and special structure and with the 8° design seismic intensity, it is necessary to analyze this sedimentation basin in the static and dynamic by 3D finite element method. This paper describes the structural model and the selected parameters for calculation of static and dynamic properties, and states the stress analysis results under the various conditions.
Authors: Ryosuke Kojima, Kouki Kitabata, Du Hong Bin, Akihiro Takita, Takao Yamaguchi, Yusaku Fujii
Abstract: Bamboo shinai is a practice sword for kendo which is the Japanese traditional fencing. The effectiveness of the shock absorption of the bamboo shinai has been shown in our previous study. Although shinai is usually made of bamboo, it is also made of carbon fiber reinforced plastic (CFRP). The impact response of bamboo shinai and CFRP shinai is compared. As a result, the difference of peak value of impact force between bamboo shinai and CFRP shinai against similar initial velocity is small. Impact response measurement of each shinai has been carried out using the Levitation Mass Method (LMM) which has been proposed by us. In this method, a mass, which is levitated with a pneumatic linear bearing and hence affected by negligible friction, is made to collide with a shinai under test. Because bamboo is natual product, resource of suitable bamboos for shinai is limited. On the other hand, carbon-fiber-reinforced-plastic (CFRP) can be designed to be suitable for a shinai, which has a fixed shock absorption characteristic for an application to the structure of robot arms. Therefore, if the shock absorption characteristic of CFRP shinai is the same as that of bamboo shinai, CFRP shinai is more suitable for the structure of robot arms.
Authors: Vladimír Taraba, Daniela Marasová, Dušan Kubala, Vladimír Semjon
Abstract: The article presents the results of the mathematical modelling of the strain and deformation conditions in the steel-cord conveyor belt of the ST 2000 and ST 2500 types, applying the Finite Element Method. The output of the model is identification of the maximum magnitude of the activated dynamic force in the conveyor belt on the basis of the analysis of vertical shifts of the loaded point, vertical strains in the area of supporting rollers, and the maximum principal strains.
Authors: Kharis Rakhimyanov, Konstantin Rakhimyanov, Anna Eryomina
Abstract: The efficiency of applying electrophysical impacts in technological methods of machine part cutting to a great extent depends on the understanding of the processes forming the basis of these impacts. As a rule a specific nature of these processes is characterized by their high intensity, locality of the impact and an impulse mode.The understanding of a certain process is necessary both for its efficient use in technological processes and for the development of new technologies based on the combination with other electrophysical impacts. The paper presents the results of mathematical modeling of deformation processes under ultrasonic frequency impulse plastic impact of a deformer on the surface layer of metals and alloys. Based on the mathematical modeling of the process of ultrasonic deformation of materials, operating parameters of the impact defining the field of application of this method are found. Quantitative relationships between basic characteristics of the deformation process and operating parameters of an ultrasonic impact are established.
Authors: Yusaku Fujii, Koichi Maru, Tao Jin, Takao Yamaguchi
Abstract: This paper reviewed the present status and the future prospects of a method for precision mass and force measurement based on levitation mass method (LMM). The LMM has been proposed and improved by the author The mass which levitated using a pneumatic linear bearing in LMM is used to producte a inertial force which used as the reference force applied to the objects under test, such as to force sensor calibration, material and structure test. The inertial force is calibrated only from Doppler shift frequency. The stability of laser’s wavelength has improved in the LMM. The futhure work and the method to improve the precision have described.
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