ボルト製品の引張試験における弾塑性挙動解析(S45-3 ねじおよびねじ締結の設計・製造・応用技術(3),S45 ねじおよびねじ締結の設計・製造・応用技術)

概要

論文の詳細を見る
The revision of ISO 898-1 is now being worked out in ISO/TC 2/SC 1/WG9, in which tensile testing method for full-size bolts has been discussed to be specified. The tensile testing was originally proposed to check the yield strength and the ductility for the cold forged products (property classes of 4.8, 5.8 and 6.8) which cannot be measured by the test using machined test pieces, and the application is going to be expanded to all the property classes for better qualification of the property. The yield strength R_<pf> of full-size bolts is defined as the stress at 0.4% non-proportional elongation, and the permanent elongation at fracture A_f (%) is calculated based on the free thread length set to 1.2d. However, the testing conditions to obtain reliable results have not fully been discussed. The aim of this paper is to clarify the elastic-plastic behavior of full-size bolt in tensile test, and to propose the appropriate figures on values in accordance with those for machined test pieces. The results from FEM analysis show that the yield property is greatly affected by free thread length, and the load-elongation curve derived from FEM analysis represents the difference between the elastic-plastic behavior of full-size bolt and machined test piece well.
一般社団法人日本機械学会の論文
2004-09-04