Impact machine. Type

More recently, explosives have been tested for impact sensitivity by an impact machine in which 40 mg of explosive on sandpaper are placed between an anvil and a steel cylinder. A 2.5 kg weight is dropped from different heights and the sound produced serves to indicate a go or no go . The result from 25 drops is calculated to give a height at which the probability of explosion is 50%. Results from a compilation104 are presented in Table 12 and show that the relative values of TNT and picric acid are reversed from the previous table. TNT is relatively more sensitive on the Type 12 impact machine than in the FI impact test. TATB is so insensitive that it fails to explode at the maximum drop height of the machine. 

Compound Impact sensitivity Type 12 machine Drop height (cm) Temperature of onset of exotherm ( C)... 

Impact Machines and Impact Tests. One frequently hears the remark that there are as many types of impact machines as there are explosives test laboratories. This is somewhat misleading. In reality, all laboratories use essentially similar equipment but test procedures, and test data analyses differ. Basically an impact machine is an apparatus that drops a steel weight from a pre-determined height onto a plunger or striker resting on top of the test sample which is placed on a steel anvil... 

Fig 2. Drop Weight Impact Machine, ERL Model, type 12 tools... 

ERL impact apparatus, type 12 This test was developed by the US Army Armament Research, Development and Engineering Center and is optional for use. The machine (Bruceton Machine) Type 12 consists of a striker pin (made of hardened tool steel, ground and polished) with surface in contact... 

Eyster R.F, Davis, OSRD Rept 5744(1945) (One type of Drop-Weight Impact Machine developed in the US during WWII) 3) Ohart (1946), 48-9, 96, 131-32, 210 380-81 4) Anon, 11 Picatinny Arsenal Testing Manual", No 2—2 (1951), p 3 5) Glossary of... 

I). E.H. Eyster L.C. Smith, "Studies of the ERL Type 12 Drop-Weight Impact Machine at NOL", NOL Memo 10003(1949)... 

K) P.E. Braid R.C. Langille, " A New Type of Impact Machine for Evaluating Sensitiveness of Explosives , CanJTech 33, 28... 

Impact resistance Relative susceptibility of plastics to fracture by shock, e.g., as indicated by the energy expended by a standard pendulum type impact machine in breaking a standard specimen in one blow. 

African oil palm nuts, which are less thick-shelled than most American palm nuts, are hand cracked to some extent but in Indonesia and Malaysia they are usually machine cracked. In one type of cracking machine, the nuts are fed to the center of a rotor equipped with curved baffles, along which the nuts are flung out against a heavy steel housing and broken by impact. Another type of machine resembles a hammer mill. The rotor consists of a frame supporting four heavy steel paddles the nuts are dropped into the path of the paddles and cracked by impact. 

Figure 12.7. Cantilever Beam (Izod Type) impact machine [ASTM D256],...

Figure 1.27. Simple beam (Charpy-type) impact machine (ASTM D 256-56).

The specimens were loaded as simple beams in a pendulum-type impact machine having a 30 lb hammer which had a velocity of 16 ft/sec at the point of impact. Specimens were tested at temperatures of 195° and 76°K using a rapid transfer of the specimen from the appropriate liquid bath to the test jig [6]. The additional testing temperatures shown in Fig. 6 were obtained by allowing speci-... 

The impact tests have been performed by using a pendulum impact machine on samples without a notch according to GOST 4746-80, type II, within the testing temperatures range r=213-333 K. Pendulum impact machine was equipped with a piezoelectric load sensor, that allows to determine elasticity modulus E and yield stress Gy in impact tests according to the techniques [8] and [9], respectively. 

Comment by E. P. Troeger, Douglas Aircraft Company, Inc, We use an impact machine which is of the type approved by the industry in general. Our results are quantitative. The detonation level we consider as acceptable is the limit of our machine, which is 185 ft-lbs. 

In common with most polymeric materials, adhesives and sealants are sensitive to the rate of applied force. There are several different types of impact test for adhesives. The most common test (similar in application to the Izod impact test for plastic materials) has been withdrawn without replacement however, the test was not widely used in a production situation due to the difficulty in achieving reproducible results. A more informative test for impact is the cleavage test in which the test specimen is subject to an impact force through a wedge (refer to Table 24). This can be initiated by a pendulum impact machine with an impact energy range of 50-300 J and an impact speed of 3-5.5 m/s. 

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