scholarly journals Transient simulation on dynamic response of liquid annular seals

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Li Song ◽  
Pingwei Chen ◽  
Tong Wang ◽  
Wensheng Ma
Keyword(s):  
Dynamic Response ◽  
Impact Load ◽  
Time History ◽  
Liquid Viscosity ◽  
Rotor Speed ◽  
Object A ◽  
Displacement Response ◽  
Sealing Pressure ◽  
Gravity Direction ◽  
Annular Seals

Transient change of the operating parameters has a serious influence on the stability of liquid annular seals. Take the liquid annular seals as a research object, a numerical method based on six-degree-of-freedom (6DOF) to analyze the dynamic response of liquid annular seals under gravity impact load. The variations of the force of liquid seal and pressure as well as the axis trajectory in time history are investigated. The influence of different sealing clearance、different liquid viscosity and different rotor speed is also studied. The results show that the maximum sealing pressure and sealing force of gravity direction will increase greatly in a very short time and then reduce rapidly. When sealing clearance increases, the displacement response amplitudes of axis trajectory, the maximum sealing force of gravity direction and maximum sealing pressure also increase. When liquid viscosity increases, the displacement response amplitudes of axis trajectory, the maximum sealing force of gravity direction and maximum sealing pressure decrease. We also found that different rotor speed has almost no influence on the maximum sealing force of gravity direction and maximum sealing pressure.

Finite Element Analysis of a Single-Layer Reticulated Dome under Impact Loading

2010 ◽  
Vol 163-167 ◽  
pp. 327-331 ◽  
Author(s):  
Liang Zheng ◽  
Zhi Hua Chen
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Impact Force ◽  
Impact Load ◽  
Residual Deformation ◽  
Time History ◽  
Single Layer ◽  
Element Analysis ◽  
Deformation Stage ◽  
The Impact

Finite element model of both the single-layer Schwedler reticulated dome with the span of 50m and a Cuboid impactor were developed, incorporating ANSYS/LS-DYNA. PLASTIC_KINEMATIC (MAT_003) material model which takes stain rate into account was used to simulate steel under impact load. The automatic point to surface contact (NODES TO SURFACE) was applied between the dome and impact block. Three stages of time history curve of the impact force on the apex of the single-layer Scheduler reticulated dome including the impact stage, stable stalemate stage, the decaying stage were generalized according to its dynamic response. It must be pointed out that the peak of the impact force of the single-layer reticulated dome increase with the increase of the weight and the velocity of the impact block, but the change of the velocity of the impact block is more sensitive than the change of weight of the impact block for the effect of the peak of the impact force, and a platform value of the impact force of the single-layer reticulated dome change near a certain value, and the duration time of the impact gradually increase. Then four stages of time history curve of the impact displacement were proposed according to the dynamic response of impact on the apex of the single-layer reticulated dome based on numerical analysis. Four stages include in elastic deformation stage, plastic deformation stage, elastic rebound stage, free vibration stage in the position of the residual deformation.

Numerical Simulation and Experimental Study on Fluid-Filled Hemispherical Shell under Impact

2013 ◽  
Vol 364 ◽  
pp. 172-176
Author(s):  
Hui Wei Yang ◽  
Bin Qin ◽  
Zhi Jun Han ◽  
Guo Yun Lu
Keyword(s):  
Numerical Simulation ◽  
Dynamic Response ◽  
Impact Load ◽  
Elastic Recovery ◽  
Plastic Hinge ◽  
Time History ◽  
Hemispherical Shell ◽  
History Of ◽  
Local Impact ◽  
The Impact

The dynamic response of fluid-filled hemispherical shell in mass impact is studied by experiment using DHR9401. Combining the time history of impact force with experimental observation of the deformation process, it can be seen that the dynamic response can be divided into four stages: the flattening around the impact point, the forming and expanding outward of shell plastic hinge, the plastic edge region flatten by the punch, and elastic recovery. The experimental results show that: Because the shell filled with liquid, the local impact load that the shell suffered is translated into area load and loads on the inner shell uniformly, so that it has a high carrying capacity. Numerical simulation is used to study the time history of energy absorption of different shell structures. The result shows that the crashworthiness of sandwich fluid-filled shell is improved greatly. Under the certain impact energy, deformation of its inner shell is very small, which can provide effective security space.

Dynamic response of circular GLARE fiber—metal laminates subjected to low velocity impact

2011 ◽  
Vol 30 (11) ◽  
pp. 978-987 ◽  
Author(s):  
George J. Tsamasphyros ◽  
George S. Bikakis
Keyword(s):  
Differential Equations ◽  
Dynamic Response ◽  
Impact Load ◽  
Equations Of Motion ◽  
Time History ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Fiber Metal Laminates ◽  
Velocity Impact ◽  
Fiber Metal

This article deals with the dynamic response of thin circular clamped GLARE fiber—metal laminates subjected to low velocity impact by a lateral hemispherical impactor. Using a spring-mass model, the differential equations of motion corresponding to loading and unloading stages of impact are derived and solved numerically. Internal damage due to delamination is taken into account. Previously published analytical formulas1,2 concerning the indentation of circular GLARE plates are used during the loading stages of impact. In this study, an equation for the unloading path is derived and used during the unloading impact stage. The load—time, position—time, velocity—time, and kinetic energy—time history responses are calculated. In this regard, the position where delamination occurs, the maximum plate deformation and the position where the impact load becomes zero are predicted. Also, the maximum impact load and the total impact duration are determined. The derived differential equations of motion are applied for GLARE 4-3/2 and GLARE 5-2/1 circular plates subjected to low velocity impact. The predicted load—time history response is compared with published experimental data and a good agreement is found. No other solution of this problem is known to the authors.

Structure Dynamic Response Analysis of Pipe String under the Action of Perforating Detonation Wave

2014 ◽  
Vol 986-987 ◽  
pp. 887-890 ◽  
Author(s):  
Xiang Sun ◽  
Zong Zhi Yang ◽  
Yun Gang Liu ◽  
Mai Quan Zhang ◽  
Yuan Fei Zhu
Keyword(s):  
Dynamic Response ◽  
Impact Load ◽  
Equivalent Stress ◽  
Time History ◽  
Response Analysis ◽  
Wave Impact ◽  
Dynamic Response Analysis ◽  
Finite Element Software ◽  
Structure Dynamic ◽  
Stress Changes

Impact load of perforation will result in strong vibration of downhole string, string operated such as bending fracture accidents. Considering the clearance between string and casing, using space beam and spring element to solve the nonlinear contact problems between oil jacket, established the numerical model of string structure dynamic response analysis in horizontal well. Extracting downhole perforation pressure wave monitoring data, using the finite element software ANSYS, analyzed the dynamic response of the tubing under perforation of detonation shock wave impact, got the displacement of the tubing、acceleration time history. The results show that, without packer, the maximum Mises equivalent stress in the end of the string, the deformation and stress changes in deflecting section of the tubing string are bigger than in vertical Wells.

Dynamic Response Measurement of 1-Inch HDD Head Arm Assembly

2010 ◽  
Vol 36 ◽  
pp. 52-56
Author(s):  
Bin Gu ◽  
Dong Wei Shu ◽  
Yusaku Fujii ◽  
Bao Jun Shi
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Frequency Shift ◽  
Impact Load ◽  
Inertial Force ◽  
Time History ◽  
Doppler Frequency ◽  
Doppler Frequency Shift ◽  
Bending Test ◽  
Element Analysis

In this paper, dynamic response of 1-inch hard disk drive (HDD) head arm assembly (HAA) against an impact load is obtained by means of a 3D non-linear finite element model in ANSYS/LS-DYNA and experiments using Optical method. A mass is modeled as a rigid body and is made to collide with the arm. The velocity, displacement, acceleration and the inertial force of the mass are obtained from the time- history of finite element analysis (FEA). In the experiment, a mass that is levitated with an aerostatic linear bearing, and hence encounters negligible friction, is made to collide with the HAA and the dynamic bending test for the arm is realized. During the collision the Doppler frequency shift of the laser beam reflecting from the mass is accurately measured using an optical interferometer. The velocity, the position, the acceleration and the inertial force of the mass are calculated from the measured time-varying Doppler frequency shift. A good correlation between the experimental data and FEA results is observed.

Dynamic Response Analysis of Butt Joint of HTS-A Steel Considering Welding Residual Stresses

2013 ◽  
Vol 423-426 ◽  
pp. 944-950
Author(s):  
Wei Shen ◽  
Ren Jun Yan ◽  
Lin Xu ◽  
Kai Qin ◽  
Xin Yu Zhang ◽  
...  
Keyword(s):  
Residual Stress ◽  
Dynamic Response ◽  
Hot Spot ◽  
Time History ◽  
High Strength ◽  
Simulation Method ◽  
Butt Joint ◽  
Welding Residual Stress ◽  
Response Analysis ◽  
Hull Structure

This paper uses both numerical simulation method and experimental research method to study on welding residual stress of high-strength steel of the cone-cylinder hull. Welding is often accompanied by a larger welding residual stress, which directly affects the safety and service life of the hull structure. In order to obtain the distribution of the welding residual stress, the welding procedure was developed by its parameter language by using FE analysis software in this paper. Then the welding residual stress of hot spot region was measured through X-ray nondestructive testing method, and compared it with simulation results. Finally, considering the residual stress as the initial stress, this paper analyzed dynamic response process of the welding structure under combined actions of the welding residual stress and multiaxial loads, which could more accurately determine the stress of welding structure and the location of fatigue risk point. According to the amplitude of damage parameters and strain time-history curve, we can estimate the fatigue life of structure by selecting the corresponding damage models.

Dynamic response of cylindrical cavity to anti-plane impact load by using analytical approach

2014 ◽  
Vol 21 (1) ◽  
pp. 405-415 ◽  
Author(s):  
Chao-jiao Zhai ◽  
Tang-dai Xia ◽  
Guo-qing Du ◽  
Zhi Ding
Keyword(s):  
Dynamic Response ◽  
Cylindrical Cavity ◽  
Analytical Approach ◽  
Impact Load

Dynamic Test of Bird Strike on a Flat Plate Made from LY-12 Aluminium

2013 ◽  
Vol 765-767 ◽  
pp. 3158-3161
Author(s):  
Jun Liu ◽  
Zheng Li Zhang
Keyword(s):  
Numerical Simulation ◽  
Dynamic Response ◽  
Dynamic Test ◽  
Time History ◽  
Aircraft Design ◽  
Bird Strike ◽  
Test Results ◽  
Valuable Data ◽  
Good Agreement ◽  
Peak Value

Tests of bird strike have been carried out on plate made from LY-12 Aluminium. The test was down with the projectile impacting the target perpendicularly at velocity of 40m/s, 80m/s, 120m/s respectively. The displacement-time history curves and strain-time history curves of on LY-12 Aluminium plate were measured. The good agreement of the results between two specimens in one group indicated that the results tested in the presnet paper are reliable. The dynamic response of the plate and damage modes of the bird influenced by striking velocity were analyzed. The peak value of the displacement linear enlarged with the increasing of the striking velocity. The test results in the present paper provided valuable data for aircraft design impacted by bird, and also provided abundant test datas for the numerical simulation model applied in bird striking.

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