The reliability of engineering products can be severely impaired by exposure to mechanical impact and shock. During manufacture, packaging, transit and service,
the shock environment plays a critical role in product survival. As a result, the simulation of a shock environment is becoming a more important aspect of product
and production testing in order to meet technical specifications.
This one-day training course provides a practical introduction to shock testing techniques. The principles of shock testing machines and the artificial generation and
measurement of shock environments will be covered, together with a review of analysis techniques and the interpretation of shock data in relation to standards and
specifications. Both classical shock and Shock Response Spectrum techniques will be covered in some detail.
The course is intended for test engineers wishing to acquire a basic understanding of shock testing techniques, and also for those concerned with type approval
testing, design assurance and reliability. It is desirable, although not essential, that delegates have an elementary knowledge of practical vibration testing such
as that provided by the CPD Dynamics short course 'Vibration Testing'.
Shock Testing Overview
- terminology; pulse types & examples; time and frequency domain; classical pulses; half-sine, final peak sawtooth and trapezoidal pulses; classical pulse shapes; pyrotechnic shock.
Shock Testing Machines
- shock machine types; free fall drop tower machines; pendulum machines; vacuum and pressure gun machines; inclined impact testers; horizontal test systems; programming waveforms; springs, crushable cones, pistons; impact without rebound.
Electrodynamic Shakers for Shock Testing
- advantages & limitations; shock spectrum synthesis; controlling pulse shapes;compensation pulses; table travel; MIL STD half sine; Wavsyn pulses; digital shock control.
Shock Measurement Techniques
- linearity; frequency and phase response; phase shifting; zero shift; accelerometer designs; piezo-resistive and piezoelectric designs;
voltage and charge amplifiers, integrated circuit PE transducers; step and system function response; temperature effects.
Shock Response Spectra
- SRS definition, generation, units and damping, derivation and interpretation; primary, positive and negative residual, maximax spectra; absolute acceleration,
relative deflection and pseudo velocity; SRS versus Fourier; SRS for classical waveforms; applications for package design; shock synthesis; wavelet synthesis.
Analysis Techniques - simple calculation procedures; inelastic and elastic impacts, coefficients of restitution;
force transmitted to foundation; time and frequency domain ; frequency analysis; wavelet synthesis.