Background technology
In recent years, both at home and abroad one after another high-strength concrete and high strength steel fibre concrete are carried out the experimental study of anti-conventional weapon penetration and blast.The materials behavior equation mainly obtains by test, and the test of this respect is also not enough.The gas big gun is the impact loading device of current experiment usefulness, the gas big gun can the transmitted at high speed bullet and test material clash into and load.The nineties, Grady etc. have just begun to utilize the gas big gun to obtain Hugoniot data under the impact compress, Yan Shaohua (the experimental study of high-strength concrete and high strength steel fibre concrete high pressure state equation, Polytechnics of PLA journal, 49-53.) etc. 2000,1 (6): carry out the plate impact experiment.The test of gas big gun requires shock wave to propagate under the state of one dimension after requiring bump usually usually, and simultaneously, this test is for convenient data processing, and hope can be adopted symmetrical impact, and therefore, design needs the bullet of impact and test block to design.
Summary of the invention
The technical issues that need to address of the present invention provide a kind of gas-gun device of testing material dynamic property, and this kind device can testing material dynamic property.
Technical solution problem of the present invention can be by taking following technical scheme:
A kind of gas-gun device of testing material dynamic property is characterized in that: the bullet that comprises and the combination of film flying, and composite member, and bullet separates with combination, the composite member of film flying; The combination of bullet and film flying comprises body and film flying, body and film flying are respectively right cylinder, the front end of body is provided with the film flying seat, this film flying seat is by inside recessed formation the in the middle part of the front end face of body, film flying places in the film flying seat, the size of film flying seat and film flying size are complementary, the sidewall wringing fit of film flying and film flying seat; Composite member is provided with at least three steps successively on same direction, be respectively equipped with sensing point on each step; The material of described composite member is identical with the material of film flying.
Technical solution problem of the present invention can also further be taked following improvement:
The middle part of the lower surface of body is inwardly recessed.
The side of body is provided with radially inwardly recessed annular groove, is provided with in the groove and makes body and the friction tight rubber ring of gun tube.
The sidewall of described film flying seat is provided with annular groove, is provided with in the groove to make film flying and the friction tight rubber ring of film flying seat.
Each sensing point is respectively equipped with probe.
Also comprise scoring ring, composite member passes scoring ring, and composite member is connected with scoring ring by epoxy resin.
The present invention has following technique effect:
Apparatus of the present invention experimentize when using, probe is installed in the inner place of step, after the combination of bullet and film flying is collided by driving of gas big gun and composite member, shock wave is to propagate in the composite member at measured material, by reading the pulse take-off time of probe location, (speed=displacement/time) obtains impacting wave propagation velocity.Show through experiment, compare that have very high precision, the result shows that this device can be used as the device of testing material dynamic property with the material parameter of standard.
Embodiment
Below in conjunction with specific embodiment the present invention is specifically described.
As shown in Figure 1 and Figure 2, the gas-gun device of testing material dynamic property, bullet that comprises and the combination of film flying 1, and composite member 2, both separate the combination 1 of bullet and film flying, composite member 2.The combination 1 of bullet and film flying comprises body 3 and film flying 4, body 3 and film flying 4 are respectively right cylinder, the front end of body 3 is provided with the film flying seat, this film flying seat is by inside recessed formation the in the middle part of the front end face of body 3, the size of film flying seat and film flying 4 sizes are complementary, film flying 4 places in the film flying seat, the sidewall wringing fit of film flying 4 and film flying seat.In order to realize wringing fit, the sidewall of described film flying seat is provided with annular groove, is provided with in the groove to make film flying and the friction tight rubber ring 5 of film flying seat.Requirement was concordant with the body front end surface or slightly high after film flying was installed on the film flying seat.The side of body is provided with radially inwardly recessed annular groove, is provided with in the groove and makes body and the friction tight rubber ring 6 of gun tube.The middle part of the lower surface of body 3 inside recessed 7.
Composite member 2 is provided with at least three steps successively on same direction, be respectively equipped with sensing point on each step, and each sensing point is respectively equipped with probe 11.The material of described composite member 2 is identical with the material of film flying 4.Also comprise scoring ring 8, composite member 2 passes scoring ring, and composite member 2 is connected with scoring ring 8 by epoxy resin 9.
As shown in Figure 2, experimentize when using, probe is installed in the inner place of step, and the combination of bullet and film flying is put in the gun tube 10.After the combination of bullet and film flying was collided by driving of gas big gun and composite member, shock wave was to propagate in the composite member at measured material, and by reading the pulse take-off time of probe location, (speed=displacement/time) obtains impacting wave propagation velocity.
Symmetrical impact is adopted in experiment, and the multiple layer combination sample has in fact just adopted one 37, and thickness is the red copper of 1cm, and probe records the mistiming of 2 positions, then D=s/t, and for symmetrical impact,
,
Be matter speed,
Be bullet speed.With the Hugoniot curve ratio of experimental result and standard, can obtain experimental error.
Usually adopt symmetrical impact in the experiment, the high velocity impact of homogeneity concrete material is just imported the speed of film flying at every turn
, the particle rapidity that obtains behind the shock wave is:
According to one group of film flying
Determine with the time that differs by the displacement of two positions with shock velocity D(), the shock velocity D and the particle velocity U of most closely knit media are linear relationships:
Obtain the value of a and b by the discrete point match.
With first be the example research experiment, first image recording.
The parameter of the closely knit medium (copper) of standard is:
A=3.94B=1.489
Adopt actual measurement to obtain
, try to achieve D with the A=3.94B=1.489 of standard, more just obtained error: Error=1-D1/D=5.6% with the actual D1 that records.Adopting uses the same method has measured different speed bump error down, and the result shows that measurement has excellent precision, and error is in 6%.
Match is carried out in experiment, obtained the impact thermal insulation of copper
Relational expression.
The test match obtains A=3.945B=1.4892 and compares with the material parameter of standard, has very high precision, and the result shows that this device can be used as the device of testing material dynamic property.
The gas-gun device of testing material dynamic property of the present invention shows through experiment after application, compares with the material parameter of standard, has very high precision, can be used as the device of testing material dynamic property.