Numerical Simulation of Load Optimization in Multi-Dimension Vibration Test

2013 ◽  
Vol 307 ◽  
pp. 236-239
Author(s):  
Jie Hu ◽  
Huai Yun Zhao
Keyword(s):  
Numerical Simulation ◽  
Equivalence Principle ◽  
Optimization Method ◽  
Shaking Table ◽  
Vibration Test ◽  
Target Response ◽  
Minimum Error ◽  
Numerical Simulation Result ◽  
Load Optimization ◽  
Control Response

This paper introduced a load optimization method in multi-dimension vibration test when the number of shaking table is less than the number of target response. The response equivalence principle is considered as response approximation, the optimization purpose is set as the minimum error between control response and target response, then the load applying in multi-dimension vibration test is analyzed stand at the point of load optimization. Genetic algorithm(GA) is used as the optimization arithmetic, and the numerical simulation result verified the effectiveness of this optimization method. The research of this paper proposed an effective way of calculating the load in multi-dimension vibration test.

Optimization Research of Multi-Point Response Control under Multi-Support Excitation in Vibration Test

2011 ◽  
Vol 52-54 ◽  
pp. 647-653
Author(s):  
Jie Hu ◽  
Da Lin Chen ◽  
Jia Quan Feng ◽  
Xi Nong Zhang
Keyword(s):  
Transfer Equation ◽  
Existence And Uniqueness ◽  
Theoretical Foundation ◽  
Control Method ◽  
Optimization Method ◽  
Vibration Test ◽  
Response Control ◽  
Numerical Simulation Result ◽  
Structure Response ◽  
Support Excitation

As an important experiment way adopted in vibration test, response control method obtained more and more attention in recent years, this paper studied the multi-point response control under multi-support excitation in vibration environment test, deduced the transfer equation set between base control excitation and structure response. After analyzing these transfer equation set, the existence and uniqueness of base control excitation was discussed, and proposed an optimization method to solve these transfer equation set based on genetic algorithm (GA). The numerical simulation result indicates the validity of the proposed optimization method. These works provided a theoretical foundation for multi-degree of freedom vibration test in a certain extent.

Numerical Simulation of Muzzle Flow Field of Gun Based on CFD

2013 ◽  
Vol 291-294 ◽  
pp. 1981-1984
Author(s):  
Zhang Xia Guo ◽  
Yu Tian Pan ◽  
Yong Cun Wang ◽  
Hai Yan Zhang
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Stokes Equation ◽  
Wave Structure ◽  
Flow Fields ◽  
Single Equation ◽  
Navier Stokes ◽  
Turbulent Model ◽  
Navier Stokes Equation ◽  
Numerical Simulation Result

Gunpowder was released in an instant when the pill fly out of the shell during the firing, and then formed a complicated flow fields about the muzzle when the gas expanded sharply. Using the 2 d axisymmetric Navier-Stokes equation combined with single equation turbulent model to conduct the numerical simulation of the process of gunpowder gass evacuating out of the shell without muzzle regardless of the pill’s movement. The numerical simulation result was identical with the experimental. Then simulated the evacuating process of gunpowder gass of an artillery with muzzle brake. The result showed complicated wave structure of the flow fields with the muzzle brake and analysed the influence of muzzle brake to the gass flow field distribution.

Geotechnical Centrifuge Shaking Table Tests and Numerical Simulation of Soil-Structure

2012 ◽  
Vol 256-259 ◽  
pp. 372-376 ◽  
Author(s):  
Jing Bo Liu ◽  
Dong Dong Zhao ◽  
Wen Hui Wang ◽  
Xiang Qing Liu
Keyword(s):  
Numerical Simulation ◽  
Soil Structure ◽  
Shaking Table ◽  
Vertical Line ◽  
Shaking Table Tests ◽  
Geotechnical Centrifuge ◽  
Centrifuge Model ◽  
Soil Structures ◽  
Input Motion ◽  
Centrifuge Model Tests

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.

Lab Testing and Finite Element Method Simulation of Hole Deflector Performance for Radial Jet Drilling

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Bin Wang ◽  
Gensheng Li ◽  
Zhongwei Huang ◽  
Tianqi Ma ◽  
Dongbo Zheng ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Low Cost ◽  
Geometric Model ◽  
Frictional Resistance ◽  
Finite Element Method Simulation ◽  
Optimization Method ◽  
Structure Design ◽  
Coal Bed ◽  
Factors Affecting ◽  
High Pressure Water Jet

Radial jet drilling (RJD) is an efficient approach for improving the productivity of wells in low permeability, marginal and coal-bed methane (CBM) reservoirs at a very low cost. It uses high-pressure water jet to drill lateral holes from a vertical wellbore. The length of the lateral holes is greatly influenced by the frictional resistance in the hole deflector. However, the hole deflector frictional resistance and structure design have not been well studied. This work fills that gap. Frictional resistances were measured in a full-scale experiment and calculated by numerical simulation. The structure of the hole deflector was parameterized and a geometric model was developed to design the hole deflector track. An empirical model was then established to predict the frictional resistance as a function of the hole deflector structure parameters and an optimization method for designing the hole deflector was proposed. Finally, four types of hole deflectors were optimized using this method. The results show good agreement between the numerical simulation and the experimental data. The model error is within 11.6%. The bend radius R and exit angle β are the key factors affecting the performance of the hole deflector. The validation test was conducted for a case hole deflector (5½ in. casing). The measured frictional resistance was decreased from 31.44 N to 23.16 N by 26.34%. The results from this research could serve as a reference for the design of hole deflectors for radial jet drilling.

The Research of Calculation Method on Vertical Natural Frequency of the New Full-Prefabricated Floor

2016 ◽  
Vol 846 ◽  
pp. 506-511
Author(s):  
Chong Fang Sun ◽  
Shu Ting Liang ◽  
Xiao Jun Zhu
Keyword(s):  
Numerical Simulation ◽  
Natural Frequency ◽  
Calculation Method ◽  
Variable Stiffness ◽  
Series Method ◽  
Numerical Simulation Result ◽  
Stiffness Method ◽  
Calculation Results ◽  
New Type ◽  
Test Result

New-type floor is composed of three kinds of slabs joined together through fittings. It is a kind of anisotropic two-way slab. In order to study the calculation method of natural frequency, series method, variable thickness method and variable stiffness method are adopted to calculate the natural frequency. The calculation results of three methods are compared with test result and numerical simulation result. The conclusion is that the calculation result of the variable stiffness method is the closest to the real natural frequency of new-type floor.

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