Software Classical shock is used for testing specimen resistance to shock impact. As the Software Classical shock is activated, at the output of shaker control system ZET 017-U there is formed a signal with pre-set parameters. Types of signals generated:
- Half-sine pulseis used to reproduce a shock occuring due to mutual collision or a sudden stop of a linear mobile system (for instance, to reproduce an elastic impact)
- Trapezoidal pulsecauses a bigger response in wide spectrum if compared to half-sine pulse. It is used if it is necessary to reproduce shock impacts similar to those which take place during space-vehicle launching at the stage of hook jettison. This pulse type is used mainly for hardware testing.
- Terminal peak sawtooth pulsewith a peak at the end of the wave – it has more even spectrum if compared to half-sine or trapezoidal pulse.
- Rectangular pulseis a particular case of trapezoidal pulse.
- Triangular pulseis a particular case of saw-tooth pulse.
Vibration tests performance
In order to start vibration tests for resistance to classical shock impact, click “Start” key. Upon its activation, the coordinate map will depict tolerance and acceleration diagrams of the previously registered shock impact.
The top right part of the interface has “Indicators of the process” section with indicators of vibration tests current status.
- Indicator “Required peak acceleration (g)” displays shock impulse set amplitude.
- Indicator “Measured peak acceleration (g)” shows peak value of the last registered shock impulse.
- Indicator “Measured peak velocity (mm/s)” shows maximum sensor vibration velocity.
- Indicator “Maximum peak displacement (mm)” displays maximum sensor vibration displacement value.
- Indicator “Maximum peak voltage (mV)” shows max generator voltage peak value.
The next section is “Transfer constant (g/V)“. “Transfer constant” indicator depicts the current average ratio of the control spectrum to that one of the generator. Above and below one can see “Transfer constant” and “Maximum transfer constant” indicators allowing to set transmission ratio measurement range, below which the tests will be stopped. In order to disable transmission ratio control, use the menu “View->Transfer characteristics” (section “Transfer constant (g/V)” will be disabled together with the corresponding indicators).
Right bottom section of the interface has a strike counter and a timer. “Common time” section shows total vibration tests duration. “Current time” section shows the time from the beginning of tests.”Number of shocks” counter shows the number of detected impacts. “Total number of shocks” counter shows the required amount of impacts in the course of tests performance. Option “Reverse count” enables changing “Number of shocks” counter values so that to depict the remaining amount of impacts. The same option allows to see the remaining test time in the section “Current time“. Vibration tests performance will be automatically stopped as the “Number of shocks” value becomes equal to “Total number of shocks” value or as “Current time” value exceeds “Total time” value.
In the course of testing, it is possible to enable “Pause” key and to suspend vibration tests performance. Clicking the same key again allows renewing tests from the moment of the pause with the same parameters as before. “Stop” key allows to stop tests performance.
In the case of unexpected pause in the vibration tests performance (due to non-compliance with vibration shaker parameters, lost connect, on and other factors) there appears a dialog window “Vibration tests suspended. Renew? Yes / No“. In order to renew vibration tests perfomance, select “Yes“, to stop vibration tests, select “No“.
Tests results saving
In the course of tests or upon their completion it is possible to generate a vibration tests report. In order to do this, use the keys “Report” and “Signals recorder“.
Upon activation of the “Report” key, there appears “Project report” window with a profile file name (see the figure below). The window depicts coordinate map with tolerance and acceleration charts. The right section contains vibration tests description.
Project report window
In order to save the report, enable “Save report” key – upon its activation there appears a dialog window offering you to save the selected vibration sensors charts as “dtu” or “rtf” file. The “dtu” files can be viewed and printed in Results view program.
In order to save information of all registered impacts, click “Signals recorder” key – it will activate “Table of registered shocks” window (see the figure below) depicting a table with all registered shocks parameters for the tests performance period.
Table with registered shocks parameters
To save the registered data to PC, use the key “Save a report”. The report is saved in “dtu” format (which can be viewed in Results view software) or in “rtf” format to be viewed in a text editor.
Note: It is not allowed to activate any other ZETLAB programs after vibration tests start or signal generator activation, since it may cause damage to the vibration shaker.
Vibration tests performance – additional information
Additional information on vibration tests performance, vibration shaker and VCS selection, equipment calibration, ZETLAB VIBRO Software functions and FAQ is available in the clause Vibration controller – integration.
In the Clause Video lesson, you can find detailed instructions on vibration test performance and preparation.