Obrabotka Metallov 2014 No. 1

ОБРАБОТКА МЕТАЛЛОВ № 1 (62) 2014 74 ОБОРУДОВАНИЕ 5. Сироткин О.С., Гришин В.И, Литвинов В.Б . Проектирование. Расчет и технология соединений авиационной техники. – М.: Машиностроение, 2006. – 331 с. 6. Беспалов В.А., Гоцелюк Т.Б . Исследование кри- териев разрушения элементов из КМ в зонах кон- центрации напряжений при сжатии: отчет по НИР №14–12. – Новосибирск: СибНИА, 2012. – 104 с. 7. Witney J.M., Nuismer R.J. Stress fracture crite- ria for laminated composites containing stress concen- trations // Journal of Composite Materials. – 1974. – Vol. 8, pp.253–265. OBRABOTKAMETALLOV (METAL WORKING • MATERIAL SCIENCE) N 1(62), January – March 2014, Pages 69–75 Numerical-experimental study of the strength of constructional elements, made of carbon laminate Kovalenko N.A. 1,2 , Post-graduate Student, Engineer, e-mail: natasha_kovalenko@ngs.ru Olegin I.P. 1 , D.Sc. (Engineering), Professor Gotseluk T.B. 1,2 , Ph.D. (Engineering), Associate Professor, Head of Sector Chaplygin V.N. 2 , Head of Department Petrov P.M. 2 , Mechanic 1 Novosibirsk State Technical University, 20 Prospect K. Marksa, Novosibirsk, 630073, Russian Federation 2 Siberian Aeronautical Research Institute named after S.A. Chaplygin, 21 Polzunov st., Novosibirsk, Russian Federation Received 12 November 2013 Revised 15 January 2014 Accepted 17 January 2014 Abstract Experimental results on the strength of laminate samples with stress concentrators of cylindrical hole- and counterformed hole-type are presented. Photographs of the samples after testing either with stress concentrators or smooth specimen with typical laminate stacking are showed. The rate of the strength reduction, obtained by means of experiments, and depending on the concentrators’ type and the material of a sample, is presented in a tabular form. Along with the experiment, a numerical evaluation of the samples’ strength with the usage of a gradient criterion (the case of compression) and Nuizmer criterion for stress in a point (the case of stretching) is conducted. Similarly, the rate of the strength reduction, obtained with the usage of criteria, are presented in a tabular form. Based on the comparison of the results obtained by numerical and experimental way, the parameters of the Nuizmer criterion corresponding to the experimental samples’ rupture stresses are offered. Guidance on the application of the considered criteria of the strength assessment to the layered composites under examination, depending on the type of stress concentrator is provided. Keywords: carbon laminate, fracture criterion, stress concentrator, degradation strength factor, strength reduction index. References 1. Tsai S.W., Wu E.M. A general theory of strength for anisotropic material. Journal of Composite Materials. 1971, Vol.5, pp. 58–80. 2. Azzi V.D., Tsai S.W. Anisotropic strength of composites. Experimental mechanics. 1965, Vol.5, pp. 283–288. 3. Norris C.B. Strength of orthotropic materials subjected to combined stresses. Forest products laboratory report. 1962, Report no.1816, pp.1–40.