YuJie_PV
Mechanical
- Jan 19, 2017
- 146
hi all,
i am reading ASME VIII-2 Annex 3-F,
3-F.1.2 reads:
(a) Carbon, Low Alloy, Series 4XX, High Alloy, and High Tensile Strength Steels for temperatures not exceeding 371°C(700°F). The fatigue curve values may be interpolated for intermediate values of the ultimate tensile strength.
and encounter some issues as follows:
1. it mentions "interpolated for intermediate values of the ultimate tensile strength". what does that mean?
is it referring to a material with UTS larger than 552 MPa (80 ksi), but less than 793 MPa (115 ksi)?
2. what if the steel subject to fatigue analysis have a temperature larger than 371°C(700°F), but still less than the temperature where creep governs?
3. both "3-F.1 SMOOTH BAR DESIGN FATIGUE CURVES" and "3-F.2 WELDED JOINT DESIGN FATIGUE CURVES" refer to fatigue curves in 3-F.5. so i am confused which kind of fatigue curves in 3-F.5 is.
4. the final one, that may i use the curve of 3-F for a steel not covered by ASME VIII-2, for example, AISI 4140?
sorry for so many fundamental questions.
thanks in advance.
i am reading ASME VIII-2 Annex 3-F,
3-F.1.2 reads:
(a) Carbon, Low Alloy, Series 4XX, High Alloy, and High Tensile Strength Steels for temperatures not exceeding 371°C(700°F). The fatigue curve values may be interpolated for intermediate values of the ultimate tensile strength.
and encounter some issues as follows:
1. it mentions "interpolated for intermediate values of the ultimate tensile strength". what does that mean?
is it referring to a material with UTS larger than 552 MPa (80 ksi), but less than 793 MPa (115 ksi)?
2. what if the steel subject to fatigue analysis have a temperature larger than 371°C(700°F), but still less than the temperature where creep governs?
3. both "3-F.1 SMOOTH BAR DESIGN FATIGUE CURVES" and "3-F.2 WELDED JOINT DESIGN FATIGUE CURVES" refer to fatigue curves in 3-F.5. so i am confused which kind of fatigue curves in 3-F.5 is.
4. the final one, that may i use the curve of 3-F for a steel not covered by ASME VIII-2, for example, AISI 4140?
sorry for so many fundamental questions.
thanks in advance.