The lab hosts two different drop towers, one bespoke and Instron 9450.  Both utilise gravity to drop a mass from a height onto the specimen therefore generating impact loading conditions. Gravity is assisted by bungy cords in our bespoke tower and springs in the Instron tower in order to achieve the desired impact speeds. We have used these machines and a sister machine (Instron Dynatup 9250-HV) in the Department of Civil & Environmental Engineering to conduct dynamic characterisation of soft and skeletal tissue, shock absorbing materials, and shock absorbing structures

The two drop towers

Technical Specifications

  • Impact velocity: 0.77-24 m/s
  • Drop height: 0.03-29.4 m
  • Mass range: 2-70 kg
  • Axial force: 0.45-222 kN
Controller and Software

The Instron 9450 is controlled by Bluehill® Impact, providing a set of pre-configured methods and testing scenarios.

Sensors
Optical

- High-speed video

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Publications

Bonner TJ, Newell N, Karunaratne A, et al. Strain-rate sensitivity of the lateral collateral ligament of the knee. J Mech Behav Biomed Mater 2015;41:261–70. doi:10.1016/j.jmbbm.2014.07.004

Newell N, Carpanen D, Evans JH, et al. Mechanical Function of the Nucleus Pulposus of the Intervertebral Disc under High Rates of Loading. Spine (Phila Pa 1976) 2019;44:1035–41. doi:10.1097/BRS.0000000000003092

Newell N, Carpanen D, Grigoriadis G, et al. Material properties of human lumbar intervertebral discs across strain rates. Spine J 2019;19:2013–24. doi:10.1016/j.spinee.2019.07.012

Grigoriadis G, Newell N, Carpanen D, et al. Material properties of the heel fat pad across strain rates. J Mech Behav Biomed Mater 2017;65:398–407. doi:10.1016/j.jmbbm.2016.09.003

Newell N, Grigoriadis G, Christou A, et al. Material properties of bovine intervertebral discs across strain rates. J Mech Behav Biomed Mater 2016;65:824–30. doi:10.1016/j.jmbbm.2016.10.012

Carpanen D, Kedgley AE, Shah DS, et al. Injury risk of interphalangeal and metacarpophalangeal joints under impact loading. J Mech Behav Biomed Mater 2019;97:306–11. doi:10.1016/j.jmbbm.2019.05.037

Newell N, Masouros SD, Pullen AD, et al. The comparative behaviour of two combat boots under impact. Inj Prev 2012;18:109–12. doi:10.1136/ip.2010.031344