3.2.5 Fatigue Strength Fibers stressed in compression St Sc Stress (a) reversal Fibers stressed in tension Neutral Neutral plane plane Sc (b PDF文件使用"pdfFactory Pro”试用版本创建ww,fineprint..com.cn
3.2.5 Fatigue Strength Stress reversal B (b) P St Sc (a) Fibers stressed in compression Fibers stressed in tension Neutral plane Neutral plane St Sc St Sc St Sc P A A B PDF 文件使用 "pdfFactory Pro" 试用版本创建 www.fineprint.com.cn
The relationship between the diameter of the rod and reversal stress applied 10.18F 1 PDF文件使用"pdfFactory Pro”试用版本创建w,fineprint..con.cn
The relationship between the diameter of the rod and reversal stress applied 3 10.18 d lF s = d F l PDF 文件使用 "pdfFactory Pro" 试用版本创建 êwww.fineprint.com.cn
o-N curves 800 Stress=620MPa 105 cycles 600 Fatigue limit =410MPa 400 Tools steel 200 Alloy aluminum 0 104 105 106 107 108 Cycles Factors stress and cycles PDF文件使用"pdfFactory Pro'”试用版本创建，fineprint.com,cn
s－N curves 104 105 106 107 108 Stress=620MPa ， 105 cycles Fatigue limit ＝410MPa Tools steel Alloy aluminum S t r e s s \ M P a Cycles 800 600 400 200 0 Factors ：stress and cycles PDF 文件使用 "pdfFactory Pro" 试用版本创建 êwww.fineprint.com.cn ê
Fatigue or endurance ratio The quotient of endurance limit to tensile strength ferrous alloys:~0.5 0 thers:0.25≈0.45 PDF文件使用"pdfFactory Pro”试用版本创建mw,fineprint..com,cn
Fatigue or endurance ratio The quotient of endurance limit to tensile strength ferrous alloys：~ 0.5 Others：0.25 ~ 0.45 PDF 文件使用 "pdfFactory Pro" 试用版本创建 ÿwww.fineprint.com.cn
Example3-3:A tool steel must be 2.44m long,and must survive continuous operation for one year with an applied load of 0.05MN.The shaft turns at one revolution per minute during operation. Design a shaft that will satisfy these requirements. Solution The total number of cycles that the shaft will experience in one year: N=(1 cycle/mim)×60x24x365=5.256x10的 cycle/year PDF文件使用"pdfFactory Pro'”试用版本创建wm,fineprint.com,cn
Example3-3：A tool steel must be 2.44m long, and must survive continuous operation for one year with an applied load of 0.05MN. The shaft turns at one revolution per minute during operation. Design a shaft that will satisfy these requirements. Solution The total number of cycles that the shaft will experience in one year： N＝（1cycle/min）´60´24´365 ＝ 5.256´105 cycle/year PDF 文件使用 "pdfFactory Pro" 试用版本创建 www.fineprint.com.cn