SU868564A1

SU868564A1 - Method of evaluating stressed state of article

Info

Publication number: SU868564A1
Application number: SU782694273A
Authority: SU
Inventors: Юрий Михайлович Стахиев
Original assignee: Центральный научно-исследовательский институт механической обработки древесины
Priority date: 1978-11-30
Filing date: 1978-11-30
Publication date: 1981-09-30

Description

Изобретение относится к неразру111ающему контролю и мо'жет быть использовано для контроля напряжений в изделиях, например, при изготовлении и подготовке дереворежущих круглых пил.The invention relates to non-destructive testing and can be used to control stresses in products, for example, in the manufacture and preparation of wood-cutting circular saws.

Известен способ оценки напряженного состояния диска путем измерения частоты собственных колебаний [1].A known method for assessing the stress state of the disk by measuring the frequency of natural vibrations [1].

Однако предлагаемый способ трудоемок, поскольку предполагает измерение амплитуды колебаний изделия.However, the proposed method is time-consuming, since it involves measuring the amplitude of the oscillations of the product.

Наиболее близким к предлагаемому по технической сущности и достигаемому результату является способ оценки напряженного состояния изделий с несколькими степенями свободы, заключающийся в том, что в контролируемом изделии возбужда’ют изгибные колебания, определяют его резонансную частоту и по ней судят о напряженном состоянии контролируемого изделия t2].The closest to the proposed technical essence and the achieved result is a method for assessing the stress state of products with several degrees of freedom, which consists in the fact that bending vibrations are excited in the controlled product, its resonance frequency is determined and the state of the controlled product is judged from it t2] .

Недостатком известного способа является низкая точность оценки напряженного состояния, связанная с предварительным измерением большого количества геометрических показателей изделия.The disadvantage of this method is the low accuracy of the assessment of the stress state associated with the preliminary measurement of a large number of geometric parameters of the product.

Цель изобретения - повышение точности контроля.The purpose of the invention is to increase the accuracy of control.

Указанная цель достигается за счет того, что дополнительно определяют вторую резонансную частоту, кон5 тролируемого изделия и по отношению этих частот используя тарированную зависимость частот, судят о его на- . пряженном состоянии.This goal is achieved due to the fact that the second resonant frequency, of the product being monitored is additionally determined, and the correlation of these frequencies using the calibrated frequency dependence is judged on it. tailed condition.

' В основе предложенного способа использована закономерность, согласно которой напряженное состояние диска различно влияет на частоты собственных колебаний диска. Так установленно, что собственные частоты ну1* левой и первой мода повышаются, а частоты второй, третьей-и т.д. мод , уменьшаются.'At the heart of the proposed method, a regularity is used, according to which the stress state of the disk differently affects the frequency of natural oscillations of the disk. It has been established that the natural frequencies well1 * of the left and first modes increase, and the frequencies of the second, third, etc. mod are decreasing.

Согласно предлагаемому способу измеряют резонансную частоту нулевой 2® или первой моды, затем, вторую резонансную частоту второй, третьей или четвертой мода, находят их отношения и сравнивают с расчетной величиной. ,According to the proposed method, the resonant frequency of the zero 2® or the first mode is measured, then the second resonant frequency of the second, third or fourth mode is found, their ratios are found and compared with the calculated value. ,

Claims

(541 METHOD FOR ESTIMATING STRESSED STATE natural oscillation frequency l. However, the proposed method of labor time, because it involves measuring the amplitude of oscillations of the product. The closest to the proposed technical essence and the achieved result is the method of estimating condition of products with several degrees of freedom, is that in controlled products excite bending oscillations, determine its resonant frequency and judge the stress state of the controlled product t2. The disadvantage of this method is the low accuracy of estimating state, associated with the preliminary measurement of a large number of geometrical parameters of the product. The purpose of the invention is to improve the accuracy of control. EQUIPMENT The specified T.P. is achieved due to the fact that the second resonant frequency of the product under test is additionally determined, and by using these calibrated frequencies, the tense state of the frequencies is used. The proposed method is based on the pattern according to which the stress state of a disk differently affects the natural frequencies of the disk. It is thus established that the natural frequencies of the zero and the first mode are increased, and the frequencies of the second, third, etc. mod are decreasing. According to the proposed method, the resonant frequency of the zero or first mode is measured, then the second resonant frequency of the second, third or fourth mode is measured, and their ratios are compared with the calculated value. The invention of the method for evaluating the stress state of products, is that in a controlled product, bending vibrations are excited, its resonant frequency is determined by it to judge the stress state of the controlled product, in order to improve the accuracy of control, In addition, a second resonant frequency of the monitored product is determined, and its tension state is judged by the ratio of these frequencies.

Sources of information taken into account in the examination

1, USSR inventor's certificate 226918, cl. G 01 L 29/04, 1963.

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2. Krivoshpykov A.P. Electronic device for monitoring the tension of diamond cutting discs. - Synthetic diamonds, 1972, 4, p. 66-69 (prototype).