Materials Characterisation and Simulation Physical Inputs to Finite Element Crash Design Tools Design Requirements Technical Service Strain Rate Data Generation, Modelling and Formatting • Controlled strain rate data generation over seven decades of strain rate up to 1000/s, conforming to Ford Premium Automotive Group test procedures, VDEh and IISI recommendations • Implementation ready material models for use in commercial finite element tools, and customised to end user application • • Material model validation • Unique lab facilities, measurement system and capability to test a wide range of materials, jointed coupons and components • Fast delivery 600 400 200 0 0 5 10 15 True Stress (Mpa) Engineering stress (MPa) 800 20 25 DP600 strain rate flow curves with IARC fitted surface 30 0 0 0.05 0.1 True Plastic Strain True Stress (MPa) Engineering Strain (%) 0.15 0.2 Development of customer specific test procedures, instrumentation and specimen designs for high rate data generation 0 0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20 True Plastic Strain Material Model Validation Joint testing specimen Material testing specimen Measured Force (kN) 14 Application Area of Technology • Improved confidence and efficiency in application of virtual testing technology to product development • Improved crashworthiness: compliance to world wide crash regulation, NCAP, insurance and pedestrian safety requirements • Reduce time, cost and risk to introduce new materials to develop new car body designs • • Reduce mass of car body structure 5000 mm/s 2000 mm/s 800 mm/s 100 mm/s 10 mm/s 12 10 8 6 4 2 0 0 10 20 30 40 Actuator Displacement (mm) End Application of Material Model Eco-friendly technology Copyright 2007 50 Materials Characterisation and Simulation Physical Inputs to Finite Element Crash Design Tools High Speed Test Laboratory, Equipment and Capability • Precision servo-hydraulic machine with closed and open loop control features • • Actuator velocity from 1 mm/s up to 20 m/s • Fast jaw Technology - acceleration of complete moving grip before testing starts • Stiff 4 column load frame for controlled testing of components and joined assemblies • Velocity profile correction under open loop control for high speed testing • High accuracy data acquisition with logging frequency of 5 MHz and 12 bit resolution • Custom built high frequency force transducers for high accuracy stress measurements • Local instrumentation fully integrated within signal conditioning unit e.g. custom built transducers and special strain gauges exposed to high speed and large strain • Modelling experiment - specimen geometry, system of measurement and test boundary conditions Controlled tensile and compression testing up to 100 kN static load (160 kN dynamic load) Medium strain rate specimen design 20.00 100 18.00 90 16.00 80 14.00 70 12.00 60 10.00 50 8.00 40 6.00 30 4.00 Strain Rate [1/s] Strain [%] Grip speed of 5 m/s: Gauge length 60 mm 20 2.00 0.00 0.037 - strain sensor strain - strain sensor strain rate 0.0375 0.038 0.039DP600 0.0395 0.04 0.0405 Load-Filtered Actuator0.0385 Position, Steel (2mm), Dynamic (5 m/s) 10 0 0.041 Time [s] 18 20.00 800 16 18.00 14 700 12 14.00 600 12.00 10 500 10.00 8 400 8.00 6 6.00 Machine Mounted Force Sensor Output 4 Mounted Forceforce Sensor Output - machineSpecimen dynamic sensor - specimen transducer 4.00 2 2.00 300 200 0.00 100 0 0.02225 0.0223 0.02235 0.0224 0.02245 0.0225 0.02255 0.0226 0.02265 0.0227 0 Dr. Paul Wood Mobile: +44 (0)7932 608084 Email: P.K.C.Wood@warwick.ac.uk LVDT Actuator Position [mm] Time [s] Dr. Claus Schley Dipl.-Ing., PhD Mobile: +44 (0)7932 729053 Email: Claus.Schley@warwick.ac.uk IARC Copyright 2008 Strain Rate [1/s] Strain [%] Load [kN] 16.00