Tiehua Ma

Implantation Dynamic Testing and Calibration Techniques

Implantation dynamic testing (or new concept dynamic testing) is the information acquisition science within severe conditions. A definition of implantation dynamic testing is presented. The implantation dynamic testing refers to a real-time live measurement of dynamic parameters of a moving object with the main part of the testing systems located within the object being tested or in the same practical environment. A set of mathematical expressions (i.e. the conditional functions) for dynamic testing is described. The main characteristics, the main substances studied and the areas of application are presented. Since the performance of testing systems in implantation dynamic testing are strongly affected by the environment forces, general calibration methods are virtually not applicable. This paper presents three layers of calibration techniques: calibrations in simulated application environments, calibrations of environment factors, and tracing calibrations of dynamic parameters (also called quasi-sigma calibration). The last one is useful in many applications.

Restraining zero drift in an ultrahigh-g impact environment

To restrain the zero drift of a piezoelectric accelerometer and the zero drift from a charge amplifier (CA) in an ultrahigh-g impact environment, a reformative design approach for an on-board ultrahigh-g deceleration–time measurement system is presented. First, a simplified zero-drift model of the on-board ultrahigh-g deceleration–time measurement system is built. Secondly, possible reasons for zero drifts in the ultrahigh-g impact environment are discussed. Then, a universal reformative CA and subsequent circuits are designed for restraining the zero drift. Finally, an air cannon is used to simulate the ultrahigh-g impact environment and a modified Michelson-type laser interferometer is set as a primary standard source to calibrate the reformative on-board measurement system. Comparisons between the measured curve and the reference curve verify that the zero drift is less than 3% of the peak value and deceleration–time data describe the real penetration process accurately. All differences in curves are not due to the proposed design and can be characterized by errors or uncertainties. Experimental results prove that the proposed design approach can restrain the zero drift effectively in the ultrahigh-g impact environment.