The BD and FBD specimens were subjected to diametral impact by the projectile with different speed using the split Hopkinson pressure bar (SHPB) of 100mm diameter with a thin aluminum circular plate as pulse shaper.
In order to investigate the dynamic tension strength of rocks,the flattened Brazilian disc specimens were subjected to diametral impact with different projectile speeds by using the split Hopkinson pressure bar(SHPB) of 100 mm in diameter where a thin aluminum circular plate was used as a pulse shaper.
Set up a standardization process about the application of numerical simulation to the split Hopkinson pressure bar experimental technique6. Effects of the diameter geometric size of pulse shaper and property parameter of material on the wave shape .
In this experiment,control pulse is temporary pulse shaped by spectrum shaping and chirped stretching,and single-longitudinal-mode laser is successfully pulse shaped in this all-optical pulse shaper,what′s more,precise synchronization between femtosecond pulse and single-longitudinal-mode shaped pulse is achieved.
The output property of this pulse shaper is numerically analyzed in theory,and the results are same as experimental ones. This all-optical pulse shaper provides a potential technical method for "fast ignition" experiment.
The distributed algorithm(DA), CSD code and modified reduced adder graph(RAG) algorithm are used to realize constant coefficients filter such as time aligned filter, HBF and raised cosine pulse shaper constant.
Both of them can expand the rising time of the wave. (2) The Hopkinson experiment with pulse shaper can modify obviously the loading wave and obtain a loading condition of a near constant strain rate by getting a slippery incident wave and decreasing the effect of the wave dispersion to eliminate high-frequency surge.
A model to predict the incident waveform in the SHPB experiment by use of a single pulse shaper is built according to the theory of stress wave. Incident waveform from experiment and model prediction with H62 brass shaper are obtained. Model predictions are in good agreement with experimental results.
To shape an incident pulse for a constant strain rate in a split-Hopkinson pressure bar (SHPB) test, a high-strength, high-work-hardening rate (HSHWHR) material was selected to fabricate the pulse shaper.
We present analytical models and data that show a broad range of incident strain pulses can be obtained by varying the pulse shaper geometry and striking velocity.
The Plexiglas or copper disk pulse shaper produces a nondispersive stress wave that propagates in the aluminum incident bar and eventually interacts with a tungsten disk at the end of the bar.
In addition, a pulse shaper lengthened the rise time of the incident pulse to ensure stress equilibrium and homogeneous deformation in the low-impedance specimen.
The use of a two-material pulse shaper allows for stress equilibrium across the specimen during the compression process, to concentrate on the initial, small deformation part that characterizes linearly viscoelastic behavior.
Control of temporal shape from a Q-switched Nd: YAG laser has been aohiened by an optical pulse shaper. A 1 ns main optical pulse, with less than 400 ps rise and fall time has been generated. The jitter time between the main pulse and the diagnosis pulse is less than 100 ps, close to the transmission-limited value of measure.
The expressions of phase distortions resulting from the misalignment of grating pair pulse shaper are presented. Their effects on the temporal aberration of output pulses, especially after focused, in ultrahigh power laser system are discussed. These results are helpful for chirped pulsed amplifier system design.
Introduced the method by which describes the function of 555 Timer with the map. By the method to analyse circuits based on 555 timer become directly preceivable and more easy. The examples of analysing pulse generator and pulse shaper by the method are also introduced.