Shock simulation method and apparatus
View Patent ↗A shock simulation test apparatus and method utilize a test plate and formed explosive charges to sever or penetrate one or more portions of a suspended test plate in order to subject any attached test item(s) to a realistic pyroshock stimulus. One or more shock measurement sensors, such as accelerometers, may be attached to the test plate or the test item(s) to measure the response to this shock stimulus. The apparatus and method is flexible in that many different scenarios can be simulated from different test plate materials, charge sizes and types. This method replicates actual end-use source shock environments typical in aerospace applications, but can be extended to any industry having a pyroshock environment and test requirement.
1. A shock simulation apparatus, comprising:
a test plate adapted to mount at least one test item; and
a first shaped charge and a second shaped charge each capable of being mounted to the test plate, the first shaped charge and the second shaped charge arranged to sever or penetrate respective portions of the test plate upon detonation; wherein:
test item is subjected to shock from detonation of the shaped charge;
the detonation of the each of the first shaped charge and the second shaped charge causes localized deformation to the test plate in the area of the first shaped charge and the second shaped charge, respectively, and does not cause significant structural deformation to the test plate in the area of the at least one test item; and
the first shaped charge and the second shaped charge are arranged to allow for repeat testing.
2. The apparatus of claim 1 , wherein the first shaped charge and the second shaped charge are selected from the group consisting of a linear shaped charge (LSC), a flexible linear shaped charge (FLSC), and a conical shaped charge (CSC).
3. The apparatus of claim 1 , wherein the test plate is comprised of a graphite-epoxy composite material.
4. The apparatus of claim 1 , wherein the test plate is curved.
5. The apparatus of claim 1 , wherein the first shaped charge is spaced apart from the test item.
6. The apparatus of claim 1 , further comprising:
at least one shock measurement sensor mounted to the test plate for measuring shock induced by detonation of the first shaped charge.
7. The apparatus of claim 1 , wherein the first shaped charge induces structural damage to the test plate limited to a detonation area.
8. A method of simulating shock, comprising:
mounting a first shaped charge to a test plate, said first shaped charge arranged to sever or penetrate a portion of said test plate upon detonation;
mounting a second shaped charge to the test plate, said second shaped charge arranged to sever or penetrate a portion of said test plate upon detonation, said first shaped charge and said second shaped charge arranged to allow for repeat testing;
mounting at least one test item to said test plate;
detonating the first shaped charge to sever or penetrate a portion of the test plate and to subject the test item to shock from detonation of the shaped charge; and
detonating the second shaped charge to sever or penetrate a portion of the test plate and to subject the test item to shock from detonation of the second shaped charge; wherein
detonating each of the first shaped charge and the second shaped charge causes localized deformation to the test plate in the area of the first shaped charge and the second shaped charge, respectively, and does not cause significant structural deformation to the test plate in the area of the at least one test item.
9. The method of claim 8 , wherein the first shaped charge and the second shaped charge are selected from a group consisting of a linear shaped charge (LSC), a flexible linear shaped charge (FLSC) and a conical shaped charge (CSC).
10. The method of claim 8 , further comprising:
measuring the shock.
11. The method of claim 8 , further comprising:
determining the condition of the test item.
12. The apparatus of claim 1 , wherein detonating the first shaped charge does not cause the test plate to bend or warp in the area of the at least one test item.
13. The method of claim 8 , wherein shock from detonation of the explosive charges arrives at the test item substantially simultaneously.
14. The method of claim 8 further comprising:
mounting a second test item to the test plate; and
detonating the second shaped charge to sever or penetrate a second portion of the test plate.
15. The method of claim 8 , wherein mounting the first shaped charge comprises mounting the first shaped charge apart from the test item.
16. The method of claim 8 , further comprising:
selecting the thickness of the test plate based on grain size of the first shaped charge.
17. The method of claim 8 , further comprising:
mounting at least one shock measurement sensor to said test plate for measuring shock induced by detonation of the first shaped charge.
18. The method of claim 8 , further comprising:
selecting the type and arrangement of the first shaped charge and the second shaped charge and the thickness of the test plate to simulate end-use operating conditions experienced by the test item.
19. The method of claim 8 , wherein mounting the first shaped charge comprises arranging the first shaped charge to confine structural damage to the test plate within a detonation area.
20. A method of testing a test item's ability to withstand shock, comprising:
detonating a first shaped charge mounted to a test plate to sever or penetrate a first portion of the test plate and impart shock into the test item, the test item being mounted to the test plate;
detonating a second shaped charge mounted to the test plate to sever or penetrate a second portion of the test plate and impart shock into the test item, wherein the first shaped charge and the second shaped charge are arranged to allow for repeat testing; and
determining the condition of the test item; wherein
the detonation of each of the first shaped charge and the second shaped charge causes localized deformation to the test plate in the area of the first shaped charge and the second shaped charge, respectively, and does not cause significant structural deformation to the test plate in the area of the at least one test item.
21. The method of claim 20 , further comprising:
measuring the shock.
22. The method of claim 20 , further comprising:
detonating the second shaped charge to sever or penetrate the second portion of the test plate to determine the test item's ability to withstand multiple detonations.
23. The method of claim 22 , wherein shock from detonation of the shaped charges arrives at the test item substantially simultaneously.
24. The method of claim 20 , further comprising:
selecting the type and arrangement of the first shaped charge and the second shaped charge and the thickness of the test plate to simulate actual operating conditions experienced by the test item.
25. The method of claim 20 , further comprising:
arranging the first shaped charge to confine structural damage to the test plate within a detonation area.
26. The apparatus of claim 1 , wherein detonation of the first shaped charge does not cause significant structural deformation to the test plate in the area of the second shaped charge.
27. The apparatus of claim 1 , wherein the first shaped charge and the second shaped charge are arranged such that if they are substantially simultaneously detonated, shockwaves from each detonation arrive at the at least one test item substantially simultaneously.
28. The apparatus of claim 1 , wherein the second shaped charge is capable of being mounted to the test plate after the detonation of the first shaped charge.
29. The apparatus of claim 1 , wherein the first shaped charge and the second shaped charge are mounted to the test plate before the detonation of either of the first shaped charge or the second shaped charge.
30. The method of claim 8 , wherein the test item is a component of an aerospace system, the method further comprising:
selecting the type and arrangement of the first shaped charge and the second shaped charge to simulate in-flight conditions experienced by the test item.
31. The method of claim 8 , wherein the second shaped charge is mounted to the test plate after detonating the first shaped charge.
32. The method of claim 8 , wherein the second shaped charge is mounted to the test plate before detonating the first shaped charge.