Tham khảo tài liệu 'modeling and simulation for material selection and mechanical design part 18', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Appendix A Continued Variable Unit Explanation Fc kN Circumferential force at screw drive flank Ft kN Tangential part of Fc tangential force Fn kN Normal part of Fc Torque Values Tt ot Nm Total torque torque applied on screw drive for assembly Ttott Nm Total torque for torque controlled tightening Tt Nm Thread torque during tightening Th Nm Head frictional torque during tightening Ttotpermt1 Nm Maximum permitted total torque which can be transmitted by the screw drive without problems during tightening T J s Nm Snug torque for angular controlled tightening Stress and Pressure Values sax MPa Axial stress in screw shank seq MPa One-dimensional equivalent stress from maximum distortion energy theory vMises theory for reducing combined stresses to one uniaxial stress value . reducing the combination of tensile- and shear stress in the screw shank to one value Sa MPa Axial stress amplitude in general Sast2 MPa Axial stress amplitude of screw at temperature t2 modulated by dynamic operating force of bolted joint Saspermt2 MPa Permitted axial stress amplitude of screw at temperature t2 modulated by dynamic operating force of bolted joint Sasperm0 MPa Fatigue limit at room temperature ISO 3800 sa max MPa Maximum shear stress in screw shank Pch MPa Pressure in contact area Ah pchmaxt1 MPa Maximum pressure in contact area Ah at temperature t1 pchmaxt2 MPa Maximum pressure in contact area Ah at temperature t2 Pct MPa Pressure in helical contact area of thread engagement normal to loaded thread flanks Pcc MPa Component contact pressure between clamped part and nut thread component Rmst1 Rmst2 MPa Tensile strength of screw at temperature t1 resp. t2 Rmnt1 Rmnt2 MPa Tensile strength of nut thread component at temperature t1 resp. t2 Rmpt1 Rmpt2 MPa Tensile strength of clamped part at temperature t1 resp. t2 MPa Proof stress with plastic strain under conditions of tensile test Es MPa Young s modulus of screw material modulus of elasticity Ep MPa Young s modulus of .
