ON INTERACTION BETWEEN MATERIAL STRENGTH AND THE STRENGTH OF STRUCTURAL ELEMENTS

MESHKOV Yuriy Ya., Corresponding member of NAS of Ukraine, D. Sc. in Eng., Chief Researcher of the Department of Physics of Strength and Fracture, Kurdyumov Institute of Metal Physics of the National Academy of Sciences of Ukraine, Kiev, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.">This email address is being protected from spambots. You need JavaScript enabled to view it.

SHIYAN Artur V., D. Sc. in Eng., Senior Researcher of the Department of Physics of Strength and Fracture, Kurdyumov Institute of Metal Physics of the National Academy of Sciences of Ukraine, Kiev, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.">This email address is being protected from spambots. You need JavaScript enabled to view it.

Based on the analysis of previously obtained experimental data, the authors of the article developed a new methodology for the assessment of structural steels ability to resist embrittling effect of stress concentrators (SC), which manifests itself in the form of loss of the bearing capacity σ_NF samples with an annular notch. The concept of a reserve of metal strength (break resistance B_r), performs the function of “clearing” local peak surges in SC zone, blocking a possible reduction in the strength of the product. The critical values of break resistance B_rb ≈ 1,6…2,2 on specimens with notch for steels with different levels of strength in the range σ_0,2 ≈ 300 ... 1500 MPa. It is proposed to use the concept of structural alloy suitability for products containing SC with a known exponent B_rb. The criterion of suitability is the structural condition of B_r ≥ B_rb. A characteristic feature of the alloy structural suitability for products with the SC is a monotonic increase in the structural strength of the product (σNF) with increasing strength of the metal σ_0,2, indicating the absence of the threat of embrittlement of the products available from the SC.

deformation endurance, break resistance, load-bearing capacity, stress concentration, structural suitability

• Meshkov Yu.Ya., Shiyan A.V., Grischenko V.N. Predely ratsionalnogo uprochnenya konstructsionuh staley [The limits of rational hardening of structural steels]. Trudy “Stroitelstvo, materialovedenye, mashinostroenye” [Proc. of the Prydniprovska State Academy of Civil Engineering and Architecture “Construction, materials science, mechanical engineering”], 2016. no. 89, pp. 112–118.
• Grischenko V.N., Meshkov Yu.Ya, Polushkin Yu.А., Shiyan A.V. Vliyanie prochnosti na ohrupchivaemost staley pod deystviem contsentratorov napryascheniy [Impact strength steels ohrupchivaemost stress raisers under the action]. Metalofizika i noveyshie tehnologii [Metal Physics and Advanced Technology], 2015. vol. 37, no 7. pp. 961–971.
• Fridman Ya.B. Mehanicheskie svoystva metalov [Mechanical properties of metals]. Мoscow, Mashinostroenie, 1974. 472 p.
• Hollomon J.H. Tensile deformation. Trans. AIME. Iron Steel Div., 1945. vol. 162, pp. 268–290.
• Kogaev V.P., Мahutov N.А., Gusenkov А.P. Raschety detaley mashyn i constructsiy na prochnost i dolgovechnost [The calculations of machine parts and structures for strength and durability]. Moscow, Mashinostroenie, 1985. 223 p.
• Kotrechko S.A., Meshkov Yu.Ya. Predelnaya prochnost. Crystaly, metaly, konstructsii [Maximum strength. Crystals, metals, constructions]. Kiev, Naykova Dumka, 2008. 295 p.
• Kotrechko S.A., Meshkov Yu.Ya., Shiyan A.V. Mehanicheskaya stabilnost — universalnaya mera soprotivleniya perehodu v hrupkoe sostoyanie metala [Mechanical stability – the universal measure of the resistance in the transition metal fragile
  state]. Uspehy fiziki metalov [The success of Metal Physics], 2009, vol. 10, no. 2, pp. 207–228.
• Meshkov Yu.Ya., Kotrechko S.A., Shiyan A.V. Mehanicheskaya stabilnost metallov i splavov [The mechanical stability of metals and alloys]. Kiev, Naykova Dumka, 2014. 278 p.
• Savin G.N., Tulchiy V.I. Spravochnik po contsentratsii napryascheniy [Directory of stress concentration]. Kiev, Vysshaya skola, 1976. 412 p.
• Shiyan A.V., Meshkov Yu.Ya. Ohrupchivanie metalicheskih splavov v usloviyah contsentratsii napryascheniy. Constructsionye stali i titanovue splavy [Embrittlement of metal alloys in the conditions of stress concentration. Structural steel and titanium alloys]. Saarbrukken, LAP LAMBERT Academic Publishing, 2015. 113 p.