Dynamic Force Measurement of Model Container to Centrifuge Nacelle Used in Centrifuge Model Explosion Test

2010 ◽  
Vol 439-440 ◽  
pp. 1393-1397
Author(s):  
Xiao Hong Yue ◽  
Yong Jian Mao ◽  
Hao Pu ◽  
Bao Liang Niu ◽  
Lei Wang ◽  
...  

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.

2013 ◽  
Vol 353-356 ◽  
pp. 495-501
Author(s):  
Lie Xian Tang ◽  
Lian Jun Guo ◽  
Da Ning Zhang ◽  
Jian Ming Zheng

The primary methods are antetype observation and model tests which to check the actual engineering status in geotechnical engineering field. The antetype observation is the best direct and convictive method, but approach miscellaneous and spend hugely. The general model tests can not fulfil the same stress between model and antetype. Geotechnical centrifuge model test can not only minish the measure of model and fulfil the comparability condition, but also can found all kinds of non-symmetrical models and simulation all kinds of complicated engineering. So the geotechnical centrifuge model test is applied widely in the geotechnical engineering. This paper used the RFPA-Centrifuge and recured to the principle of geotechnical centrifuge model test, evaluated the safety of model only by increase the physical strength. Though the numerical calculating in nonhomogeneous models with different scales showed that stress, displacement and failure mode were accord with conform ratio of centrifuge model tests. Showed the advantage that the results of RFPA can be validated each other with results of physical tests. For some specifical complicated items in geotechnical engineering, make a good test model is not only very hard and have to spend much time, but also need expensive test equipment and much money for test materials. It is very good if we can use a method to conquer these shortages. So it is advisable that using the mechod which geotechnical centrifuge tests combine RFPA-Centrifuge numerical simulation analysis method.


2021 ◽  
Vol 12 (1) ◽  
pp. 81
Author(s):  
Inyeop Chu ◽  
Sang-Kyun Woo ◽  
Sang Inn Woo ◽  
Joonyoung Kim ◽  
Kicheol Lee

Due to the lack of surface space, most structures are heading underground. The box culvert is underground infrastructure and serves to protect the buried structure from the underground environments, but it has a different characteristic from other structures in that the inner space is empty. Therefore, in this study, the vertical earth pressure which is the most significant effective stress acting on a box culvert was measured by conducting a geotechnical centrifuge model test. A box culvert was installed following the embankment installation method, and the vertical earth pressure acting on it was measured considering the cover depth, gravitational acceleration, and loading and unloading conditions. The soil pressure measured was greater than the existing theoretical value under high cover depth and the unloading condition, which is considered as the variability of many soils or the residual stress acting under the loading condition. Finally, a goodness-of-fit test was conducted as a part of variability analysis. The measured earth pressure was found to be considerably larger than the existing theoretical value, and the variability was large as well. This means the existing theoretical equation is under-designed, which should be reflected in future designs.


2016 ◽  
Vol 16 (8) ◽  
pp. 1719-1735 ◽  
Author(s):  
Minggao Tang ◽  
Qiang Xu ◽  
Yusheng Li ◽  
Runqiu Huang ◽  
Niek Rengers ◽  
...  

Abstract. About 18 years ago, a large-scale discontinuous layer in properties and colour was found in the new Fengjie town at the shore of the Three Gorges Reservoir area in China. There are many resettled residents and buildings on the sloping area, the safety of which is potentially affected by this layer, so it has become the focus of attention. Before this study started there were two viewpoints regarding the origin of this layer. One was that is was from a huge ancient slide and the other was that is was from a fault graben. In order to find out how it was formed and to be able to carry out a stability analysis of the slope the authors have carried out a research program, including geological field investigations and mapping, a deep drilling hole, a geotechnical centrifuge model test, and a simulation analysis. The results of the research led to the conclusion that the layer is the sliding plane of a huge deep-seated ancient rock slide, which we called the Sanmashan landslide. An important argument for the conclusion is the recognition of a regional compressive tectonic stress field in this area, which cannot lead to the formation of a fault graben because it needs a tensional tectonic stress field. Moreover, numerous unique geological features, sliding marks, and other relics of the ancient slide have been discovered in the field. The formation process of the ancient slide could be repeated in a large geotechnical centrifuge model test. The test shows that a deformation and failure process of "creep–crack–cut" has occurred. The type of the ancient slide can be classified as a "successive rotational rock slide". Finally, the role of seepage in the stability of the Sanmashan landslide has been analysed. Our final conclusions are that, during rainfall and filling–drawdown cycles in the Three Gorges Reservoir, the Sanmashan landslide as a whole is dormant and stable and the secondary landslides in the toe area of the slope are presently stable but can be reactivated. This research provides an important basis for the remedial measures and land use planning in the new Fengjie town, and a well-documented case history for researchers worldwide.


Author(s):  
Murat Fidan ◽  
Alper Bayrak ◽  
Umid Karli

In this study, a low-cost and adaptable isometric strength measurement and exercise development system are described. The implemented system consists of mechanical structure, force measurement sensor, electronic circuit, and computer software. Isometric-isotonic (via spring resistance) strength analysis and various exercise programs can be applied with the system. The developed system has a lower cost compared to its counterparts in the literature and has a structure that can be adapted to different machines and measuring methods. The operability and reliability of the isometric strength measurement and exercise development system have been proven by calibration tests.


2019 ◽  
Vol 39 (4) ◽  
pp. 388-396 ◽  
Author(s):  
Peng Zhao ◽  
Yao Zhao ◽  
Jianfeng Zhang ◽  
Junye Huang ◽  
Neng Xia ◽  
...  

AbstractAn online and feasible clamping force measurement method is important in the injection molding process and equipment. Based on the sono-elasticity theory, anin situclamping force measurement method using ultrasonic technology is proposed in this paper. A mathematical model is established to describe the relationship between the ultrasonic propagation time, mold thickness, and clamping force. A series of experiments are performed to verify the proposed method. Experimental findings show that the measurement results of the proposed method agree well with those of the magnetic enclosed-type clamping force tester method, with difference squares less than 2 (MPa)2and errors bars less than 0.7 MPa. The ultrasonic method can be applied in molds of different thickness, injection molding machines of different clamping scales, and large-scale injection cycles. The proposed method offers advantages of being highly accurate, highly stable, simple, feasible, non-destructive, and low-cost, providing significant application prospects in the injection molding industry.


Author(s):  
Y. S. Kim ◽  
K. O. Kim ◽  
Y. Cho ◽  
S. Bang ◽  
K. D. Jones

An analytical solution has been developed to estimate the inclined pullout capacity of an embedded suction anchor in clay seafloor. Validation has been made through comparisons with a limited number of centrifuge model test results. Results indicate that the inclined pullout capacity of an embedded suction anchor in clay decreases as the load inclination angle to the horizontal increases. As the point of the load application moves downward, the inclined pullout capacity increases, reaches its peak, and then starts to decrease.


2012 ◽  
Vol 256-259 ◽  
pp. 372-376 ◽  
Author(s):  
Jing Bo Liu ◽  
Dong Dong Zhao ◽  
Wen Hui Wang ◽  
Xiang Qing Liu

Two geotechnical centrifuge model tests of a soil-structure system with different burial depths are performed to investigate the interaction between soil and structure. The tests are performed at 50 gravitational centrifuge accelerations and the input motion is Kobe wave. This paper focuses on the accelerations and displacements in the soil-structures system. The peak accelerations and displacements along the axis of the structure and along the vertical line 17cm away from the axis are presented. The acceleration and displacement response due to the interaction between soil and structure are studied.


Sign in / Sign up

Export Citation Format

Share Document