Magnetorheological suspension damper for space application Ing. Michal Kubík Supervisors Doc. Ing. Ivan Mazůrek, CSc. Ing. Jakub Roupec, Ph.D. Institute of Machine and Industrial Design Faculty of Mechanical Engineering Brno University of Technology Brno, February 2018
MOTIVATION Current solution New solution 2/30
CONTENTS Introduction The aim of the thesis Magnetorheological suspension damper New methods for design of MR damper with short response time Conclusion 3/30
INTRODUCTION Passive Active Semi-active Passive vibration isolation system Spring and passive damper Reliable Relatively cheap No external power supply Composite cone; specaflightnow.com Moog soft ride system; Johnson(2006) Honeywell vibration isolation platform; Hindle (2005) 4/30
INTRODUCTION Active Active vibration isolation system Electric actuator Provide better comfort of payload than passive Usually large weight, large power demmands High cost Hybrid D-strut system with voice coil; Coob (1999) 5/30
INTRODUCTION Semi-Active Semi-active (S/A) vibration isolation system Spring and controlled damper S/A control = switching on and off the damping force comfort of payload is similar to active; depending on parameter damping element Relatively new in space area S/A control vibration platform? Honeywell vibration isolation platform; Hindle (2005) 6/30
INTRODUCTION Honeywell D-Stut system Design of D-Stut system Bellows elements Damping element Bellows D-strut system; Coob (1999) Project: Semi-Active Damping System Bellows New S/A controlled damping element 7/30
MAGNETORHEOLOGICAL FLUID Damping elements for S/A Control Electro-hydraulic damping element (8-25 ms) Qin (2016); Shin (2004) Electrorheological damping element (typically 10 ms) Koyanagy (2010); Gurka (2010) Magnetorheological damping element (typically 20 ms - 300 ms / 1.5 ms) Koo (2006); Yang (2002); Mass (2011), Strecker (2015) Shortest response time 8/30
MAGNETORHEOLOGICAL FLUID Magnetorheological fluid Magnetorheological damper Ferromagnetic particles Carrier fluid Magnetorheological damper; Jolly(1999) Magnetorheological effect; Grundwald (2008) 9/30
SEMI-ACTIVE CONTROL EFFICIENCY The efficiency of Semi-active control is influenced by: Response time Dynamic force range (set-up ratio) D v, H = F ON v, H F OFF v Electric current-switching on 10/30
LITERATURE REVIEW Frequency requirements of ESA and Honeywell Literature review of suitable materials Frequency vibration control requirement up to 25 Hz Response time 4 ms 4 ms New and special design of magnetorheological damper with short response time Response time of MR damper Response time of MR fluid itself (0.45-0.6 ms); Gonclaves (2005) Inductance of MR damper coil (with current controller 0.5 ms) Strecker (2015) Eddy currents in coil core (depending on electric resistivity) Strecker (2015); Mass (2011) Ferrite or SMC material Design problem: low strength and fragility 11/30
LITERATURE REVIEW How to obtain the response time of MR damper in design phase? Transient magnetic model of MR damper Takesue (2003); Zheng (2015) In the literature insufficiently described sub-aim of the thesis How to obtain the geometry of bypass gap? Common design of MR valve Force shock at low piston velocity Bypass gap Hydraulic model of bypass gap; Sohn (2015) In the literature insufficiently described sub-aim of the thesis 12/30
THE AIM OF THE THESIS Main aim: Development and test of magnetorheological suspension damper with short response time for space application The sub-aims are as follows: a method to decrease the response time of MR damper, magnetic models and their experimental verification, a model of bypass gap and its experimental verification, experimental verification of published hydraulic models. 13/30
SECTIONS OF THE THESIS Main aim of the thesis Design of magnetorheological suspension damper with short response time Sub-aims of the thesis Experimental verification of new models and methods Concept of MR damper Simulation models Design of MR valve Production and assembly Experiments 14/30
CONCEPT OF MR SUSPENSION DAMPER Design of MR damper New models Magnetorheological suspension damper is composed of: bellows unit, external MR valve, bypass gap Semi-active vibration isolation system Bellows unit Bypass gap S/A control MR valve 15/30
SIMULATION OF MR VALVE Design MR damper The geometry of the MR valve was determined by hydraulic and magnetic models New methods Geometry and material properties Hydraulic model of active zone iteration process Damping forces Hydraulic model of MR damper Magnetostatic model Hydraulic model of bypass gap 16/30
HYDRAULIC MODEL OF MR VALVE Design MR damper Hydraulic model of active zone of MR damper New methods Input to the model Model Output from the model Geometry of active zone Apparent viscosity of MR fluid Yield stress of MR fluid (output from magnetostatic model) Non-Newtonian behavior of MR fluid Equation published by Yang (2002) Damping forces dependent on piston velocity 17/30
HYDRAULIC MODEL OF MR VALVE Design MR damper Hydraulic model of bypass gap New methods Input to the model Model Output from model Geometry of bypass gap Apparent viscosity of MR fluid CFD model More detailed description in the next section Pressure drop dependency on flow rate (slope of F-v in low piston velocity) 18/30
MAGNETOSTATIC MODEL OF MR VALVE Design MR damper Magnetostatic model New methods Input to model Model Output from model Magnetic material properties Geometry of active zone Ansys Maxwell 2D axisymmetric Geometry was simplified Coil parameters Dimension of magnetic circuit Magnetic flux density (input to the hydraulic model) Magnetic flux in magnetic circuit of the MR valve 19/30
DESIGN OF MR VALVE Design MR damper Geometry based on hydraulic and magnetic models New methods Gap 0.6 mm Length of active zone 34 mm 3 coil configuration (allows modularity) Lord MRF-122EG Design respects low strength of ferrite New design of the MR valve 20/30
Coil power supply MATERIAL SELECTION Design MR damper New methods Low carbon steel Problem - fabricating of ferrite parts Plastic Ferrite Aluminium 21/30
MR SUSPENSION DAMPER Design MR damper MR valve was connected to Bellows unit Pressure, stroke and temperature sensor New methods Expansion chamber 22/30
MEASUREMENT OF F-v-I Design MR damper New methods Materials and methods Logarithmic sweep 0.1 Hz to 8 Hz Stroke 5 mm Current from 0 A to 1 A Results Damping force 1380 N (0.08 m/s) Dynamic force range (set-up ratio) was 8 (0.065 m/s) Maximum model error was 18 % SS 23/30
Time response [ms] MEASUREMENT OF RESPONSE TIME Design MR damper New methods Materials and methods Damping force, stroke and electric current Sampling frequency 10 khz Rise and drop of damping force Response time = 63.2 % of steady state damping force Response time: 12 10 8 6 Results Rise 4.1 ms (v > 0.08 m/s) Drop 3.6 ms Switching ON Results published in top engineering Switching OFF journal Smart Materials and Structures 4 2 IF 2.909 Q1 0 0 0.05 0.1 0.15 Bellows velocity [m/s] 24/30
SECTIONS OF THE THESIS Design magnetorheological suspension damper with short response time Experimental verification of new models and methods Hydraulic model of bypass gap Transient magnetic model Elimination of eddy currents 25/30
HYDRAULIC MODEL OF BYPASS GAP Design MR damper New methods Hydraulic model of bypass gap Transient magnetic model Elimination of eddy currents Model and results published in conference proceedings in WOS Model CFD model Ansys CFX k-ε turbulent model Experimental verification Developed test device 2 types of MR fluid 3 different diameters and lenghts of bypass Results Maximum error of model 24 % Developed test device The model allows the effective design of the bypass. 26/30
Response time [ms] TRANSIENT MAGNETIC MODEL Design MR damper New methods Hydraulic model of bypass gap Transient magnetic model Elimination of eddy currents Model and results published in conference proceedings in Scopus Model Ansys Electromagnetics 17.0 2D axisymmetric Experimental verification Geometry MR damper Hall probe on the air Results Maximum error of model 28 % The model allows to determine the response time in the MR damper for a specific design and material of magnetic circuit. 3 2.5 2 1.5 1 0.5 0 Comparison of response time control current rise-model control current rise-experiment control current drop-model control current drop-experiment 0 0.5 1 1.5 2 Electric current [A] 27/30
ELIMINATION OF EDDY CURRENTS Design MR damper New methods Hydraulic model of bypass gap Transient magnetic model Elimination of eddy currents Problem with ferrite material Main idea Increase the path where the eddy currents can flow Shape approach grooves Test samples 48 grooves Electro erosive wire Results 4.6 x drop of response 28/30 time
ELIMINATION OF EDDY CURRENTS Design MR damper New methods The idea was extended to magnetic circuit made from small ferromagnetic rods 3D metal printing Hydraulic model of bypass gap Transient magnetic model Elimination of eddy currents Czech patent application PV 2017-91 PCT application 29/30
CONCLUSION Main aim of thesis Sub-aims of thesis Results published in top engineering journal Smart Materials and Structures 2 x Conference proceedings in Scopus or WOS IF 2.909 Q1 Czech patent application PV 2017-91 The results of my thesis allow to design ultra-fast magnetorheological damper PCT patent application 30/30
THANK YOU FOR ATTENTION Ing. Michal Kubík Michal.Kubik@vutbr.cz www.ustavkonstruovani.cz