Investigation into the dynamic characteristics of downhole perforation tools with multiple shock absorbers

2019 ◽  
Vol 20 (6) ◽  
pp. 622
Author(s):  
Xiaoqiang Guo ◽  
Jun Liu ◽  
Guorong Wang ◽  
Qingyou Liu ◽  
Xianming Song
Keyword(s):  
Dynamic Characteristics ◽  
Field Experiments ◽  
Shock Absorber ◽  
Response Amplitude ◽  
Ansys Software ◽  
Maximum Acceleration ◽  
Shock Absorbers ◽  
Tubing String ◽  
Testing Instruments ◽  
Multiple Shock

The use of large-charged perforating bullets after well perforation produces large impact loads, which can easily lead to early unsealing of packers, damage to testing instruments, stress failure of tubing strings, buckling deformation, and other adverse incidents. This study focuses on the safety of large-charged perforating bullets used in downhole tools. In addition, a dynamic model of downhole perforation tools with multi-shock absorber was designed, and ANSYS software was used to validate its accuracy. Perforation impact loading field experiments were developed, and the loading pressure was measured over time to obtain an even more accurate equation to calculate loading. Analysis of the effects of different numbers of shock absorbers on the dynamic characteristics of downhole tools was conducted, finding that increasing the number of shock absorbers from one to two significantly decreased the dynamic response amplitude of the downhole tools (displacement, axial force, and packer force). However, when the number was increased to three, the change in response amplitude was not significant. Based on the maximum acceleration of each section of the tubing string, the testing instrument is best installed at its upper end. As the number of shock absorbers is increased, the number of regions of the tubing string that undergo buckling deformation decreases. Increasing the number of shock absorbers helps prevent buckling deformation in the tubing string, and increases its service life.

Comparisons Between Dynamic Characteristics of Pneumatic, Magnetorheological, and Hydraulic Shock Absorbers

2012 ◽  
Author(s):  
A. M. Salem ◽  
S. Olutunde Oyadiji
Keyword(s):  
Dynamic Characteristics ◽  
Shock Absorber ◽  
Testing Machine ◽  
Mr Damper ◽  
Nonlinear Behaviour ◽  
Hydraulic Shock ◽  
Shock Absorbers ◽  
Wide Range ◽  
Force Velocity ◽  
Force Displacement

The dynamic performance of automotive vehicles is influenced by the suspension system design. Suspensions owing damping elements with a wide range of non-linear behaviour can provide higher mobility and better ride comfort performances. Pneumatic suspensions due to their inherent nonlinear behaviour can provide high mobility performance while suspensions with MR dampers can provide this nonlinearity through the controllable damping force produced by the control of the MR fluid. The pneumatic and MR suspension models are usually developed from experimental force-displacement and force-velocity characteristics. The purpose of this paper is to measure and compare the dynamic characteristics of pneumatic, magnetorheological, and hydraulic shock absorbers. The study is carried out through measuring the characteristics of the different types of dampers at different frequencies and amplitudes using an Electro-Servo Hydraulic (ESH) testing machine. The shock absorber is subjected to sinusoidal excitation of frequency varying from 0 to 10 Hz, and amplitude varying from 0 to 10 mm. In the case of the MR damper, the tests are also done at different current levels of between 0 and 2 amp. The input displacement and acceleration to the shock absorber were measured using an LVDT (Linear Voltage Displacement Transducer) and an accelerometer, respectively while the input velocity was derived from the measured displacement and acceleration. This dual identification of the input velocity was done in order to ensure accurate representation of the velocity. The output force response of the shock absorber was measured by means of a force transducer. The force-displacement and force-velocity characteristics of each shock absorber were subsequently derived from the measured data. The results show the tunability of the MR damper characteristics in comparison to those of the pneumatic and hydraulic dampers.

Mathematical modelling and experimental validation of mono-tube shock absorber

2016 ◽  
Vol 13 (4) ◽  
pp. 294-299 ◽  
Author(s):  
Lalitkumar Jugulkar ◽  
Shankar Singh ◽  
Suresh Sawant
Keyword(s):  
Experimental Validation ◽  
Shock Absorber ◽  
Numerical Data ◽  
Damping Force ◽  
Response Curves ◽  
Flow Area ◽  
Maximum Acceleration ◽  
Content Type ◽  
Shock Absorbers ◽  
Frequency Ratios

Purpose The work presented in this paper is concerned with mathematical modeling and experimental validation of mono-tube shock absorber. This paper aims to create damper model to predict accurately damping force, and experimental analysis is done by varying the various parameters, such as flow area in bleed(Ab), mass (M) and operating frequency(?). Design/methodology/approach Here, input is given in the form of sinusoidal excitation, and the output is received as a numerical data of the displacement transmissibility. These data are then processed to get the values of transmissibility and magnification factor for various frequency ratios. They are then plotted to have transmissibility and frequency response curves, as it is a generally accepted measure of how well the system is isolated from its surroundings. Findings It is better to have low transmissibility (larger bleed area), for lower suspension velocity, as it will reduce maximum acceleration transmitted to the sprung mass. However, for higher suspension velocity, bleed area should be low (higher transmissibility) to reduce displacement of tyre from road. Originality/value The development of faster vehicles and also the requirements of smoother and more comfortable rides have led to the fitment of dampers on almost on all present day vehicles. Shock absorbers have a significant influence on handling performance and riding comfort. Shock absorber plays an important role not only for comfort of the riders of the vehicle but also in the performance and life of the vehicle. However, no further reduction of vehicle vibration can be expected for using the optimum values of damping coefficient and spring stiffness for the shock absorber. Thus, it is necessary to make modification to improve the functions of shock absorber.

Simulation of Aircraft Landing

2018 ◽  
pp. 1-10
Author(s):  
S. G. Dzhamgarov ◽  
V. I. Oleynikov ◽  
V. A. Trudonoshin ◽  
V. G. Fedoruk
Keyword(s):  
Mathematical Model ◽  
Field Experiments ◽  
Shock Absorber ◽  
Three Dimensional ◽  
Soft Landing ◽  
Shock Absorbers ◽  
Aircraft Landing ◽  
Recovery Stroke ◽  
Object Oriented Approach ◽  
The Mathematical Model

The article proposes a mathematical model of the aircraft landing upon touchdown operation. The mathematical model can be used at the early design stages to select the rational parameters of shock absorbers to ensure soft landing. Unlike most of the papers in the field concerned, it describes the simulation of the aircraft's run-out process rather than the first touchdown impact or Dynamic Drop Testing. This is due to the use of three-dimensional mathematical models of mechanical systems, including the aircraft body. In addition to the forces on the aircraft, the article gives a sufficiently detailed representation of the forces that arise in the shock absorber. The simulation results obtained using the PA8 complex developed at the CAD Department in Bauman Moscow State Technical University are presented. The diagrams presented show the effect of the clearance in the chambers of recovery stroke on the operation of shock absorbers and, as a consequence, on ensuring the soft landing conditions. An object-oriented approach, implemented in the complex, allows us to evaluate the influence of each element on the system dynamics. The article presents the time diagrams of the force of a gas spring taking into account the dry friction and the hydraulic force in the shock absorber. In conclusion, a rational, in authors’ opinion, approach to designing shock absorbers is shown. One of the points of this approach is the validation of shock absorber parameters based on the results of Dynamic Drop Testing and, after that, simulation of the aircraft landing with validated parameters. Such a technique will allow us to minimize the number of field experiments, and as a result, will shorten the design time and put the product into operation.

Electrorheological Squeeze-Flow Shock Absorber

1999 ◽  
Vol 13 (14n16) ◽  
pp. 2143-2150 ◽  
Author(s):  
Boris Khusid ◽  
Andreas Acrivos ◽  
Yakov Khodorkovsky ◽  
Michael Beltran
Keyword(s):  
Electric Field ◽  
Field Experiments ◽  
Shock Absorber ◽  
Squeeze Flow ◽  
Heavy Duty ◽  
Shock Absorbers ◽  
Test Conditions ◽  
Flow Through ◽  
Induced Stresses ◽  
Er Fluids

We developed a squeeze-flow shock absorber and tested it under impact conditions typical of heavy-duty recoil mechanisms. In contrast to common shear-flow shock absorbers, here the volume of fluid driven by the piston does not flow through the regions of high electric field. Experiments on three commercially available "dry" ER fluids showed that only the Bayer fluid was able to exhibit electric-field-induced stresses under our test conditions. But the results which were obtained with this fluid illustrate the numerous advantages to be gained by utilizing a squeeze-flow shock absorber in advanced systems subjected to impact disturbances and destructive vibrations.

Mathematical modeling of elastoplastic deformation of tubular energy-absorbing elements under static and impact loading

2020 ◽  
pp. 78-82
Author(s):  
A.Р. Evdokimov ◽  
A.N. Gromyiko ◽  
A.A. Mironov
Keyword(s):  
Mathematical Modeling ◽  
Impact Loading ◽  
Elastoplastic Deformation ◽  
Shock Absorber ◽  
Analytical Models ◽  
Dynamic Impact ◽  
Shock Absorbers ◽  
Energy Absorbing ◽  
Absorbing Elements

Analytical models of static and dynamic impact elastoplastic deformation of tubular energy-absorbing elements constituting a tubular plastic shock absorber are proposed. The developed models can be used for the calculation and design of these shock absorbers. Keywords static and dynamic elastoplastic deformation, mathematical modeling, tubular energy-absorbing element, tubular plastic shock absorber, impact loading. [email protected]

Dynamics Characteristics for Contact Surface of Machine Tool

2014 ◽  
Vol 538 ◽  
pp. 91-94
Author(s):  
Wei Ping Luo
Keyword(s):  
Machine Tool ◽  
Dynamic Characteristics ◽  
Contact Surface ◽  
Dynamic Performance ◽  
Virtual Prototype ◽  
Prototype Model ◽  
Ansys Software ◽  
Dynamic Analyses ◽  
Contact Surfaces

A virtual prototype model of Machine Tool has been constructed by using the Pro/E software and the ANSYS software. Considering the effects of contact surfaces, dynamic analyses of Machine Tool are studied. The effects of contact surfaces on the dynamic characteristics of machine tool are studied. So that the purpose predicting and evaluating synthetically the machine tool dynamic performance without a physical sample can be achieved.

scholarly journals Application of an Additive Manufactured Hybrid Metal/Composite Shock Absorber Panel to a Military Seat Ejection System

2021 ◽  
Vol 11 (14) ◽  
pp. 6473
Author(s):  
Valerio Acanfora ◽  
Chiara Corvino ◽  
Salvatore Saputo ◽  
Andrea Sellitto ◽  
Aniello Riccio
Keyword(s):  
Numerical Simulation ◽  
Additive Manufacturing ◽  
Total Mass ◽  
Shock Absorber ◽  
Metal Composite ◽  
Plastic Deformations ◽  
Shock Absorbers ◽  
Numerical Assessment ◽  
Lattice Core ◽  
Ejection Phase

In this work, a preliminary numerical assessment on the application of an additive manufactured hybrid metal/composite shock absorber panels to a military seat ejection system, has been carried out. The innovative character of the shock absorber concept investigated is that the absorbing system has a thickness of only 6 mm and is composed of a pyramid-shaped lattice core that, due to its small size, can only be achieved by additive manufacturing. The mechanical behaviour of these shock absorber panels has been examined by measuring their ability to absorb and dissipate the energy generated during the ejection phase into plastic deformations, thus reducing the loads acting on pilots. In this paper the effectiveness of a system composed of five hybrid shock absorbers, with very thin thickness in order to be easily integrated between the seat and the aircraft floor, has been numerically studied by assessing their ability to absorb the energy generated during the primary ejection phase. To accomplish this, a numerical simulation of the explosion has been performed and the energy absorbed by the shock-absorbing mechanism has been assessed. The performed analysis demonstrated that the panels can absorb more than 60% of the energy generated during the explosion event while increasing the total mass of the pilot-seat system by just 0.8%.

Double Adjustable Shock Absorbers Utilizing Electrorheological and Magnetorheological Fluids

2000 ◽  
Author(s):  
Jason E. Lindler ◽  
Norman M. Wereley
Keyword(s):  
Shock Absorber ◽  
Force Measurements ◽  
Damping Force ◽  
University Of Maryland ◽  
Shock Absorbers ◽  
Piston Head ◽  
Performance Requirements ◽  
Velocity Response ◽  
The University ◽  
Yield Force

Abstract Double adjustable shock absorbers allow for independent adjustment of the yield force and post-yield damping in the force versus velocity response. To emulate the performance of a conventional double adjustable shock absorber, an electrorheological (ER) and magnetorheological (MR) automotive shock absorber were designed and fabricated at the University of Maryland. For the ER shock absorber, an applied electric field between two tubular electrodes, located in the piston head, increases the force required for a given piston rod velocity. For the MR shock absorber, an applied magnetic field between the core and flux return increases the force required for a given piston rod velocity. For each shock absorber, two different shaped gaps meet the controllable performance requirements of a double adjustable shock absorber. A uniform gap allows for control of the yield force of the shock absorber, while a non-uniform gap allows for control of the post-yield damping. Force measurements from sinusoidal displacement cycles, recorded on a mechanical damper dynamometer, validate the performance of uniform and non-uniform gaps for adjustment of the yield force and post-yield damping, respectively.

On-Field Measurements of the Dissipated Vibrational Power of an SUV Car Traditional Viscous Shock Absorber

2018 ◽  
Author(s):  
Mohamed A. A. Abdelkareem ◽  
Lin Xu ◽  
Mohamed Kamal Ahmed Ali ◽  
Mohamed A. Hassan ◽  
Ahmed Elagouz ◽  
...  
Keyword(s):  
Shock Absorber ◽  
Average Power ◽  
Field Measurements ◽  
Velocity Range ◽  
Suspension Systems ◽  
Shock Absorbers ◽  
Road Section ◽  
Speed Range ◽  
System Body ◽  
Acceleration Signals

The current paper provides some on-field measurements regarding the quantification of the dissipated power during the damping process of a traditional viscous shock absorber. In this regard, the HAVAL H8 SUV was driven for several trips on the Nanhu campus arena considering a velocity range of 20–50 km/h. Furthermore, two species of campus road sections were selected during the fabricated tests; straight road section with and without a speed bump. The acceleration signals of the rear-right suspension system (body and wheel) were acquired as the average power dissipation trend could be calculated from the relative suspension velocity. The findings of this investigation indicate that the average dissipated power of a traditional shock absorber can be in a range of 10–90 W for a speed range of 20–50 km/h driving on a campus road section free of speed bumps. Whilst, for another road segment with one speed bump, the shock absorber dissipated a kinetic energy between 40–140 W for a velocity range of 20–50 km/h. Suggesting that an average overall dissipated power of 160–560 W is available by means of the traditional shock absorbers. The results are of strategic interest for the researchers and vehicle manufacturers for further considerations in terms of regenerative suspension systems where a part of this energy could be harvested instead of being wholly dissipated.

Modelling the Dynamic Behaviour of A Motorcycle Damper

1995 ◽  
Vol 209 (4) ◽  
pp. 249-262 ◽  
Author(s):  
A L Audenino ◽  
G Belingardi
Keyword(s):  
Shock Absorber ◽  
Dynamic Behaviour ◽  
Fluid Dynamic ◽  
Critical Factor ◽  
Physical Models ◽  
Vehicle Suspension ◽  
Shock Absorbers ◽  
Internal Fluid ◽  
Output Force ◽  
Dependent Behaviour

Within the context of vehicle suspension component characterization, that of shock absorbers is one of the more difficult to achieve, yet it is a very critical factor in the prediction of vehicle dynamic behaviour. Strongly non-linear output force functions are always linked to a frequency-dependent behaviour. Using the internal fluid-dynamic phenomenon with respect to a motorcycle shock absorber, different physical models of increasing complexity are presented: using these models it is possible to evaluate the importance of different factors, for example oil compressibility or oil inertia. Comparisons with experimental data confirm the validity of these models

Sign in / Sign up

Export Citation Format

Share Document