Determination of stresses and residual life in accordance with indications of variable-sensitivity integral strain gauge
The relevance. The urgent problems of any stage of mechanical engineering development are the reduction of time for design and mastering the production of new items of machines, and the increase in their reliability and life-time. The period for the item follow-on can be shortened by experimental me...
| Main Authors: | , |
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| Format: | Article |
| Language: | Russian |
| Published: |
Tomsk Polytechnic University
2017-11-01
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| Series: | Известия Томского политехнического университета: Инжиниринг георесурсов |
| Subjects: | |
| Online Access: | http://izvestiya.tpu.ru/archive/article/view/1927 |
| _version_ | 1797813141207252992 |
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| author | Vladimir Nikolaevich Syzrantsev Ksenia Vladimirovna Syzrantseva |
| author_facet | Vladimir Nikolaevich Syzrantsev Ksenia Vladimirovna Syzrantseva |
| author_sort | Vladimir Nikolaevich Syzrantsev |
| collection | DOAJ |
| description | The relevance. The urgent problems of any stage of mechanical engineering development are the reduction of time for design and mastering the production of new items of machines, and the increase in their reliability and life-time. The period for the item follow-on can be shortened by experimental methods that allow determining the character of cyclic stresses (strains) distribution along the investigated part surfaces, estimating their serviceability and fatigue strength at the initial stages of testing. The opportunities of experimental methods are essentially expanded when the level of cyclic stresses is assessed by means of integral strain gauges made of a foil having certain characteristics. The long-term experience of applying the integral strain gauges indicate that they can be used to establish a wide range of problems on determining the character of surface stress variation for parts and load-carrying elements of machines, recovery of the stress distribution law, determination of equivalent stresses, assessment of location and terms of probable fractures of items within the stand and operation tests of machines. At the same time, implementation of the developed techniques for integral strain gauges applying during operation of the items revealed a number of problems related to both monitoring the integral strain gauges-reaction and uncertainty of the testing time because of the incubation period of the gauge prior to appearance of its reaction. The important problem of forecasting the life-time of parts, metallic structures of machines, oil and gas pipes that are subjected to a random spectrum of cyclic strain is the assessment of the accumulated fatigue damages of the metal. This problem solution demands the development of models that relate the reaction on the integral strain gauges to the level of damages occurred in operation of the gauged item. The aim of the study is to develop the variable-sensitivity integral strain gauge that is characterized by a variable sensitivity to the amplitude of cyclic loads without the incubation period. This gauge allows simplifying considerably the registration of variable-sensitivity integral strain gauge reaction at any moment of the item testing; to develop the techniques for solving the problems of forecasting the life-time of machine parts and oil and gas pipe elements, that is the technique for stress measurement, the analysis of equivalent stresses and equivalent numbers of loading cycles in accordance with the damaging effect. The methods used in the study: the kinetic theory of mechanical fatigue, numerical methods for solving the transcendental equations, the strength of materials. The results. The paper considers the technique for producing variable-sensitivity integral strain gauge. The authors have determined the variation of accumulated damages (obtained within the preliminary operating time of the gauge) for the operating part of the gauge without reaction based on the kinetic theory of mechanical fatigue. The problems of stress determination and forecasting the median number of cycles prior to fracture of the item based on variable-sensitivity integral strain gauge indications were solved. For operating conditions of the item at the block mode of loading the reaction of variable-sensitivity integral strain gauge was used to determine the equivalent stress according to the damaging effect and the equivalent strain according to the damaging effect of the numbers of cycles. |
| first_indexed | 2024-03-13T07:47:56Z |
| format | Article |
| id | doaj.art-65bd72e78a9247bbb5785449ede3c206 |
| institution | Directory Open Access Journal |
| issn | 2500-1019 2413-1830 |
| language | Russian |
| last_indexed | 2024-03-13T07:47:56Z |
| publishDate | 2017-11-01 |
| publisher | Tomsk Polytechnic University |
| record_format | Article |
| series | Известия Томского политехнического университета: Инжиниринг георесурсов |
| spelling | doaj.art-65bd72e78a9247bbb5785449ede3c2062023-06-02T21:11:17ZrusTomsk Polytechnic UniversityИзвестия Томского политехнического университета: Инжиниринг георесурсов2500-10192413-18302017-11-013289Determination of stresses and residual life in accordance with indications of variable-sensitivity integral strain gaugeVladimir Nikolaevich SyzrantsevKsenia Vladimirovna SyzrantsevaThe relevance. The urgent problems of any stage of mechanical engineering development are the reduction of time for design and mastering the production of new items of machines, and the increase in their reliability and life-time. The period for the item follow-on can be shortened by experimental methods that allow determining the character of cyclic stresses (strains) distribution along the investigated part surfaces, estimating their serviceability and fatigue strength at the initial stages of testing. The opportunities of experimental methods are essentially expanded when the level of cyclic stresses is assessed by means of integral strain gauges made of a foil having certain characteristics. The long-term experience of applying the integral strain gauges indicate that they can be used to establish a wide range of problems on determining the character of surface stress variation for parts and load-carrying elements of machines, recovery of the stress distribution law, determination of equivalent stresses, assessment of location and terms of probable fractures of items within the stand and operation tests of machines. At the same time, implementation of the developed techniques for integral strain gauges applying during operation of the items revealed a number of problems related to both monitoring the integral strain gauges-reaction and uncertainty of the testing time because of the incubation period of the gauge prior to appearance of its reaction. The important problem of forecasting the life-time of parts, metallic structures of machines, oil and gas pipes that are subjected to a random spectrum of cyclic strain is the assessment of the accumulated fatigue damages of the metal. This problem solution demands the development of models that relate the reaction on the integral strain gauges to the level of damages occurred in operation of the gauged item. The aim of the study is to develop the variable-sensitivity integral strain gauge that is characterized by a variable sensitivity to the amplitude of cyclic loads without the incubation period. This gauge allows simplifying considerably the registration of variable-sensitivity integral strain gauge reaction at any moment of the item testing; to develop the techniques for solving the problems of forecasting the life-time of machine parts and oil and gas pipe elements, that is the technique for stress measurement, the analysis of equivalent stresses and equivalent numbers of loading cycles in accordance with the damaging effect. The methods used in the study: the kinetic theory of mechanical fatigue, numerical methods for solving the transcendental equations, the strength of materials. The results. The paper considers the technique for producing variable-sensitivity integral strain gauge. The authors have determined the variation of accumulated damages (obtained within the preliminary operating time of the gauge) for the operating part of the gauge without reaction based on the kinetic theory of mechanical fatigue. The problems of stress determination and forecasting the median number of cycles prior to fracture of the item based on variable-sensitivity integral strain gauge indications were solved. For operating conditions of the item at the block mode of loading the reaction of variable-sensitivity integral strain gauge was used to determine the equivalent stress according to the damaging effect and the equivalent strain according to the damaging effect of the numbers of cycles.http://izvestiya.tpu.ru/archive/article/view/1927integral strain gaugesvariable sensitivitykinetic theory of mechanical fatiguecyclic stressesfatigue damagesequivalent stresses |
| spellingShingle | Vladimir Nikolaevich Syzrantsev Ksenia Vladimirovna Syzrantseva Determination of stresses and residual life in accordance with indications of variable-sensitivity integral strain gauge Известия Томского политехнического университета: Инжиниринг георесурсов integral strain gauges variable sensitivity kinetic theory of mechanical fatigue cyclic stresses fatigue damages equivalent stresses |
| title | Determination of stresses and residual life in accordance with indications of variable-sensitivity integral strain gauge |
| title_full | Determination of stresses and residual life in accordance with indications of variable-sensitivity integral strain gauge |
| title_fullStr | Determination of stresses and residual life in accordance with indications of variable-sensitivity integral strain gauge |
| title_full_unstemmed | Determination of stresses and residual life in accordance with indications of variable-sensitivity integral strain gauge |
| title_short | Determination of stresses and residual life in accordance with indications of variable-sensitivity integral strain gauge |
| title_sort | determination of stresses and residual life in accordance with indications of variable sensitivity integral strain gauge |
| topic | integral strain gauges variable sensitivity kinetic theory of mechanical fatigue cyclic stresses fatigue damages equivalent stresses |
| url | http://izvestiya.tpu.ru/archive/article/view/1927 |
| work_keys_str_mv | AT vladimirnikolaevichsyzrantsev determinationofstressesandresiduallifeinaccordancewithindicationsofvariablesensitivityintegralstraingauge AT kseniavladimirovnasyzrantseva determinationofstressesandresiduallifeinaccordancewithindicationsofvariablesensitivityintegralstraingauge |