Double Pendulum Dynamic Tear

Dynamic Tear testing in accordance with ASTM E604, and Drop Weight Tear Testing in accordance with ASTM E436, require either pendulum type or drop tower type test machines.  MPM manufactures both drop tower machines (see our Drop Tower web page) and double pendulum machines which satisfy the requirements of E436 and E604.

MPM Double Pendulum Machine

System Features

As discussed in the ASTM standards, the capacity needed to conduct tear tests on most steels is 2000 ft-lbs.  The double pendulum machine pictured here is a 2000 ft-lb machine.  MPM can provide machines of any desired capacity (ex, 30,000 ft-lb  or higher).  Double pendulum machines are provided with 21,000 count encoders for accurate total absorbed energy measurement (0.3 ft-lb accuracy).  If requested, double pendulum test machines can be provided with instrumented strikers (see our Instrumented Impact Testing web page).   Some important features of the MPM double pendulum machine are listed below:

  • Rigid frame construction and precision bearings minimize energy loss
  • Encoder energy measurement accurate to within 0.3 ft-lb on a 2000 ft-lb machine
  • Motorized pendulum return system with computer control
  • Velocity setting hardware so the impact velocity can be varied
  • Computer controlled pneumatic release
  • Safety latches
  • Impact v4.3 software with system control, automatic data acquisition, and post-processing data base analysis capability


The double pendulum impact test machine can be provided with several options:

  • Instrumented striker system (Instrumented Impact Testing)
  • In-situ heating & cooling system (In-Situ Heating & Cooling)
  • Precision specimen centering tool