The measurement technique of leftover stress

Blind aperture law: Its principle is the bore on the primitive stress field below balance position, with purify one part has the metal of stress, and make the stress inside partial metal gets near round hole flabby, bore was destroyed original stress balances position and make stress distributings afresh, present new stress to balance, make the metal near round hole produces displacement or strain thereby, carry the instrument of meet an emergency of tall sensitivity, measure the meet an emergency after bore to measure, can calculate the stress value of former stress field. Measure an instrument; Appearance of meet an emergency; Blind aperture is gotten; Meet an emergency is beautiful. 2.

X ray law: X ray stress determines the method is to use X ray diffraction to determine the means that meet an emergency of the crystal lattice in sample seeks a workpiece surface stress. But because χ is smooth,stress determines the measurement of appearance precision is poorer.

Suit to be used at determining to have the work of greater leftover stress quite, like common program, weldment, quench etc. З .

Magnetic law: Magnetic law measures leftover stress is to use the effect pressing magnetism of iron magnetism material to be namely below stress action.

On each direction of iron magnetism material guide magnetism rate produces distinct change, produce magnetism thereby anisotropy.

Determine through what change to guiding magnetism is led the method that will decide leftover stress. This law still is in experiment or try out phase at present, my place is undertaking discussing adoption the possibility of this method. Concerned data processing method is in scientific test, having much test data, but sometimes these data can not make our be clear at a glance, and be arranged through what to these data has science and analyse, can help us sum up an a lot of phenomena and ask carry. Current, this asks carry notice and take seriously what had caused more and more Scientists and Technologists, the data that precision of dimension of every batches of test specimen in our experiment carries a gender is hundreds of, get on more than 1000 even, because this is preliminary,the attempt manages with a few simple number statistical method analysis.

Arranged large quantities of test data, obtained certain result. 4.

Measure error analysis: Apply method of several manage statistic to undertake an analysis to much data.

When arranging, often should use arithmetical average (X) reach deviation (S) its expression is: Use the average level that represents measured value commonly. With the 8 fluctuant circumstances that will measure measured value, s is bigger, the wave motion of the measured value that express a name is bigger, s is small, explain measure compare concentration. In computation.

When analysing change of precision of slideway of workpiece of oscillatory effectiveness for a given period of time to measure, the deviation size of reading repeats when the basis is measured, can the deviation that cipher out measures is worth S, when deflection is less than S, should think to not was out of shape or be out of shape not remarkable. CNC Milling