An approach for assessing the accuracy of accelerometer responses during axial impact tests

The primary objective of the present study is to show that for the most common configuration of an impactor system, the accelerometer cannot exactly reproduce the dynamic response of a specimen subjected to impact loading. An equivalent Lumped Parameter Model (LPM) of the given impactor set-up has been formulated for assessing the accuracy of an accelerometer mounted in a drop-weight impactor set-up for an axially loaded specimen. A specimen under the impact loading is represented by a non-linear spring of varying stiffness, while the accelerometer is assumed to behave in a linear manner due to its high stiffness. Specimens made of steel, aluminium and fibre-reinforced composite (FRC) are used in the present study. Assuming the force-displacement response obtained in an actual impact test to be the true behaviour of the test specimen, a suitable numerical approach has been used to solve the governing non-linear differential equations of a three degrees-of-freedom (DOF) system in a piece-wise linear manner. The numerical solution of the governing differential equations following an explicit time integration scheme yields an excellent reproduction of the mechanical behaviour of the specimen, consequently confirming the accuracy of the numerical approach. However, the spring representing the accelerometer predicts a response that qualitatively matches the assumed force-displacement response of the test specimen with a perceptibly lower magnitude of load.

Basic research in crashworthiness II - low speed impact tests of unmodified vehicles. Interim technical report.

National Highway Traffic Safety Administration, Washington, D.C.

Basic research in crashworthiness II - low speed impact tests of modified vehicles. Interim technical report.

National Highway Traffic Safety Administration, Washington, D.C.

25.0 mph 26 degree crabbed moving barrier impact tests into a 26 degree load cell barrier face. Test #1: NHTSA deformable barrier face. Test #2: EEVC deformable barrier face. Test report.

Mode of access: Internet.

Light truck aggressivity study - test report 1 - truck-to-car head-on impact tests. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Light truck aggressivity study - test report 2: truck-to-car 90 degree left side impact tests. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Van crashworthiness and aggressivity study - test report 2: van-to-car head-on impact tests. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Light truck aggressivity study. Test report 3: truck-to-car right offset impact tests. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Van crashworthiness and aggressivity study. Test report I: van-to-NHTSA fixed test device head-on impact tests. Volume I. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Review of head rotational measurements during biomechanical impact tests. Technical report.

Mode of access: Internet.

Impact tests of human subjects using a prototype air bag restraint system. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Impact tests of a near-production air cushion restraint. Final report.

National Highway Traffic Safety Administration, Office of Vehicle Structures Research, Washington, D.C.

Impact tests of a near-production air cushion restraint.

Mode of access: Internet.

Analysis of Combined Bending and Punching Tests of Reinforced Concrete Slabs within IMPACT III Project

The paper reports on a collaborative effort between the Swiss Federal Nuclear Safety Inspectorate (ENSI) and their consultants Principia and Stangenberg. As part of the IMPACT III project, reduced scale impact tests of reinforced concrete structures were carried out. The simulation of test X3 is presented here and the numerical results are compared with those obtained in the test, carried out in August 2013. The general object is to improve the safety of nuclear facilities and, more specifically, to demonstrate the capabilities of current simulation techniques to reproduce the behaviour of a reinforced concrete structure impacted by a soft missile. The missile is a steel tube with a mass of 50 kg and travelling at 140 m/s. The target is a 250 mm thick, 2,1 m by 2,1 m reinforced concrete wall, held in a stiff supporting frame. The reinforcement includes both longitudinal and transverse rebars. Calculations were carried out before and after the test with Abaqus (Principia) and SOFiSTiK (Stangenberg). In the Abaqus simulation the concrete is modelled using solid elements and a damaged plasticity formulation, the rebars with embedded beam elements, and the missile with shell elements. In SOFiSTiK the target is modelled with non-linear, layered shell elements for the reinforcement on both sides; non-linear shear deformations of shell/plate elements are approximately included. The results generally indicate a good agreement between calculations and measurements.