droptest {droptest}R Documentation

droptest: Simulates LOX drop testing.

Description

Generates simulated data representing the LOX drop testing process (also known as impact testing). Drop testing is expensive, time consuming, and notoriously difficult to analyze. A simulated process allows for accelerated study of test behavior.

Details

Functions are provided to simulate trials, test series, and groups of test series. Functions for creating plots specific to this process are also included. Test attributes and criteria can be set arbitrarily. This work is not endorsed by or affiliated with NASA.

Drop testing – sometimes called impact testing – is used to evaluate if a material will interact with liquid oxygen (LOX). The material is exposed to the LOX and an impactor is dropped onto the sample. Each drop is a bernoulli trial where a reaction is a failure and a non-reaction is a success. The specified number of trials – until failure – completes one test.

While fundamentally a binomial process, drop testing – performed by the military and NASA – yields results that are difficult to analyze. Numerous tech briefs and standards have attempted to address the problem (see below for more information). Testing stops immediately once the failure condition is reached. If the failure condition occurs on drop one or two – depending on the failure criteria – then the test returns only one or two result values. Alternatively, if a material passes, or if the failure condition occurs on the last trial, then the test returns as many result values as trials.

Simulation can be used to examine the behavior of this test procedure.

Inspired by NASA Technical Note "Computer Simulation of Threshold Sensitivity Determinations" (NASA-TN-D-7663). Gayle (1974). https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19750004618.pdf

Definitions

Author(s)

Chad Ross chad.ross@gmail.com

References

Pass/Fail criteria and number of observations required have been defined in the following standards:

Note: This package is not constrained by any standard. Arbitrary test criteria and observations can be specified for maximum flexibility.

For more information on drop testing:

Note: This work is not endorsed by or affiliated with NASA. Released under MIT license.

See Also

dtrials dseries dgroups trialdev gayleplot ratioplot D7905 PREGENTD


[Package droptest version 0.1.3 Index]