Since speed can be varied, it can simulate actual impact values at high-speeds. This sophisticated impact test provides full force and energy curves during the millisecond of the impact, using a "Tup" which incorporates an impact head and a load cell. The data is often used to specify appropriate materials for applications involving impact. The test is also used to evaluate the effect of secondary finishing operations or other environmental factors on plastic impact properties. Since many materials especially thermoplastics exhibit lower impact strength at reduced temperatures, it is sometimes appropriate to test materials at temperatures that simulate the intended end use environment.
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A number in parentheses indicates the year of last reapproval. A superscript epsilon e indicates an editorial change since the last revision or reapproval. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. NOTE 1—This speci? The only similarity between the two tests is that they are both instrumented impact tests.
The differences in striker,? Terminology 3. This test method further provides a measure of the rate sensitivity of the material to impact. Therefore, results should be compared only for specimens of essentially the same thickness, unless speci?
Therefore, it is advisable to refer to that material speci? Table 1 of Classi? Interferences 5. For further de? Apparatus 6. The hole edges shall be rounded to a radius of 0. Sufficient force must be applied mechanically, pneumatically, or hydraulically to prevent slippage of the specimen in 2. Referenced Documents 2. Current edition approved December 10, Published February Originally approved in Last previous edition approved in as D - If other plunger or hole sizes are used they shall be highlighted in the report.
Correlations between various geometries have not been established. This can be accomplished through the use of a suitable transducer or potentiometer attached directly to the system. Photographic or optical systems can also be utilized for measuring displacement. The recording apparatus shall record load and displacement simultaneously. For further information, see A1. Most of them include computerized data reduction and automatic printouts of results.
Test Specimen 7. In general, the minimum lateral dimension should be at least 13 mm greater than the diameter of the hole in the clamp see 6. Conditioning 8. NOTE 2—To facilitate high throughput during automated testing at temperatures other than ambient, it is often necessary to stack the specimens in a column with no air? To assure compliance with Section 10 of Practice D , the time to equilibrium must be determined for a given material.
A thermocouple may be placed at the center of a specimen stack in which its height is equal to its minimum width. Determine the time to reach equilibrium at the desired test temperature. Experiments with materials having low thermal conductivity values have shown that more than 7.
Two and a half additional hours were needed to reach equilibrium. Speed of Testing 9. Procedure Tighten the clamping plate in such a way as to provide uniform clamping pressure to prevent slippage during testing. The testing speed movable-member velocity at the instant before contact with the specimen shall be as follows: Some suggested speeds are 2. If there is evidence of slippage, modify the clamping conditions or increase the specimen size and repeat test procedures.
Calculation The point for determining this has not been standardized. Therefore, the point used for each test must be stated in the report. NOTE 2—Thicknesses were: aluminum, 0. Report Precision and Bias Ten specimens from each material were sent to each participating laboratory. Each test result was the average of 5 individual determinations.
Each laboratory obtained 2 test results for each material. The data in Tables should not be applied to acceptance or rejection of materials, as these data only apply to the materials tested in the round robin and are unlikely to be rigorously representative of other lots, conditions, materials, or laboratories.
Users of this test method should apply the principles outlined in Practice E to generate data speci? The principles of R is the interval representing the critical difference between two test results for the same material, obtained by different operators using different equipment in different laboratories.
Keywords This includes, but is not limited to, strain gage force transducers, piezo-electric force transducers and accelerometers.
In addition, the transducer must have the durability to survive repeated impact tests without change in output from its initial calibrated state.
NOTE A1. One application might de? Another might de? Appendix X1, X1. For testing involving extremely tough materials, it may be necessary to locate the transducer further from the impact point to prevent damage.
Generally, this class of materials will produce a high loading impact event with a long tf. This is due to the damping effect of the test specimen itself as well as the large magnitude of the loading event in comparison to the initial oscillation produced by the transducer assembly. This includes, but is not limited to, oscilloscopes, data loggers, and computer based data acquisition systems.
The following are system recommendations: A1. These recordings may have useful or important characteristics beyond those required in Section These additional parameters may be reported when identi?
It must be emphasized that the load-displacement recordings are dependent on specimen geometry, size, thickness and testing speed. The loaddisplacement recordings may also display signals or artifacts that are the result of physical or electrical contributions from the test device.
If the source of these contributions can be veri? Comparisons should only be made between equivalent specimens and test conditions. The following are examples of some characteristics that have been found useful or may affect the interpretation of the test data.
NOTE X1. Generally, when a material has a high toughness and a low to medium stiffness, the inertial effects will occur early in the test and not affect the data required in Section However, some brittle materials, possessing high stiffness and low toughness, will often show inertial effects or system ringing, or both, persisting to the point of?
For related information, see X1. This crack or damage can often be proven by use of controlled penetration or controlled energy input.
This is of value where the crack or damage in the part constitutes failure. It is also valuable in composite materials where it signi? Precautions must be taken to compare only data from specimens of the same thickness and test conditions.
It can be used as the point of onset of plastic damage. It is specimen and test condition dependent. Some of the most common are multiple peaks when testing a matrix material or multiple slope changes when testing a? The inclusion of the area under all of the peaks is often important, especially when the total energy absorbed by the part is signi? The operator must de? The failure may be obvious if the load drops to zero with little or no increase in displacement.
A percent drop in load from the peak is one type of criteria used. If the probe is a one-piece design from the load transducer to the impact point, the portion of the loaddisplacement recording that follows penetration represents the friction effect of the probe sliding through the puncture and has no utility for describing the impact fracture.
The specimen is in one piece after the penetration and the deformed material exhibits plastic? Each contains features of both and should be speci?
These may be indicative of cracks, tears, or failure of individual components in a composite. If they are signi? See Fig. Care must be taken to ensure that the zero slope points are not caused by inertial effects.
See X1. This is especially true when brittle failures are encountered.
Multiaxial Impact ASTM D3763, ASTM D7192, ISO 6603, ISO 7765