Oscillatory effectiveness for a given period of time eliminates the research of stress of remains of aluminium alloy test specimen
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- source:KOMANG CNC Machining
Stress of 3 tests remains uses bore law to measure the leftover stress of aluminium alloy test specimen, this is a kind of more mature method [8, 9] , its are basic the thought is one alveolus is gotten on the member that has leftover stress, make be released as a result of partial stress inside the adjacent region of aperture and the meet an emergency with corresponding generation, measure these meet an emergency, via can reaching bore manages original stress after conversion. Because bore law is a kind of ruinous measurement technique, according to experimental requirement, dope some nods the leftover stress value of oscillatory around, such ability are made quite, and it is very difficult that leftover stress is measured 2 times in same point, it is this to be able to be solved by the following method, if the graph is shown 3 times, if want to measure A to nod the leftover stress value of oscillatory around, the surface of the same cross section that nods in A controls each apart 10mm to be in dot of choice A ′ and A ″ to nod, the circumstance of leftover stress change that the leftover stress value that can measure A ′ dot and A ″ place respectively through oscillatory around so will come to sentence A to nod, the basis of law of this one party is: It is we had done leftover stress to determine to the test specimen before to load, the leftover stress value that discovers its surface is roughly equal, field of cloth of approximate Yu Jun; 2 it is to load means it is central place suffers test specimen carry, bring about test specimen to make bend be out of shape, on the coping that the same horizontal stroke that reason nods in A carries a scale at 3 o'clock A, a ′ , the leftover stress value after A ″ is uninstalled is roughly equal; 3 it is the fundamental that accords with bore law. 1.
Effectiveness for a given period of time of vibration of 4 oscillatory ageing treatment is in what proper time brings to bear on near the resonance frequency of component part or structure to stimulate with vibrator namely brace up, reduce the goal with leveling remains stress in order to achieve. To all pledging for fine grain, different bearing form, its natural frequency is different, what use in this experiment is the mechanical model that 2 end secure, its are first-order natural frequency can press type gets: By on the first-order natural frequency that type can get the system after two end secure test specimen makes an appointment with 436Hz. When the experiment, of the experiment stimulate Zhen Pin rate to should be gotten by signal generator sweep around 436Hz, move stress value to succumb at material not quite 1/3 ultimate, the join of experiment instrument is shown 4 times like the graph, stimulate around resonance dot brace up time is controlled commonly control in 15min. Nextpage2 test result and data processing 2.
1 experiment chooses 3 to nod on the 1 test specimen that grows in 800mm, if pursue,5 are shown. Oscillatory around place measures gotten A, b, the result of the leftover stress that C3 nods is shown 7 times like the graph. Be being reduced from what stress of oscillatory around remains can see in the graph is apparent. 2.
2 experiments choose 5 to nod on the 2 test specimen that grow in another 800mm, if pursue,6 are shown. Oscillatory around place is measured A, b, c, d, the edge that E5 nods advocate if the leftover stress result of stress direction pursues show 8 times. 3 analysises and discuss (2) is experimenting 1 in, brace up before the limits is worth region of leftover stress is - 7.
2~34.
2MPa, and brace up hind turn into - 25.
6~5.
3MPa, brace up hind than brace up before the value region of leftover stress dropped 25.
4% . Experimenting 2 in, brace up before value region is - 12.
6~31.
9MPa, brace up hind value region is - 16.
0~11.
0MPa, brace up hind than brace up before the value region of leftover stress dropped 39.
3% . By afore-mentioned analysises knowable, leveling of oscillatory effectiveness for a given period of time the leftover stress of test specimen, and the effect is more apparent also. 4 conclusion can see from inside the experiment above and analysis: To ageing treatment of vibration of aluminium alloy component, can more apparent ground is reduced and stress is worth leveling remains, can conclude then going out to use technology of oscillatory effectiveness for a given period of time at component of other nonferrous metal also is feasible. Of course, when the project uses this technology actually, still remain at accumulating experience further, choose each parameter reasonably. CNC Milling CNC Machining