PP=P×〔1-e-(kx+μθ)〕/(KL+μθ),这里面的θ是怎么来的,θ----从张拉端至计算截面曲线孔道部分切线的夹角之和,rad,能具体说明一下吗?最好有实例,非常感谢!
θæ¯å¾çº¸ç»çï¼çæ¸ æ¥æ¯å¼§åº¦è¿æ¯è§åº¦ï¼è®¡ç®æ¯ç¨è§åº¦çï¼æ³¨æ转æ¢ã
é¢ç»çº¿ï¼1ï¼
θï¼2.86°ï¼0.04992ãK:0.0015 U=0.23 ãAP=140mm2
EPï¼194333ããRï¼8m
æ²çº¿é¿ï¼Lï¼Î¸R=0.04992Ã8ï¼0.399mÃ2=0.798m
ç´çº¿é¿L=ï¼209.9+17.56/2-17.5+100.3+40+15ï¼Ã2=730.52=7.3052m
伸é¿é计ç®å ¬å¼ï¼â³Lï¼(ç´)ããâ³Lï¼(æ²)å³â³Lï¼
Ppï¼
计ç®kxï¼uθ=0.0015Ã0.399+0.23Ã0.04992ï¼0.01208
e-ï¼kx+uθï¼=0.98799
PPï¼ï¼
ï¼
ï¼1385.762Mpa
â³Læ²ï¼1385.762Ã140Ã0.399Ã1000/(140Ã194333)*2ï¼5.6904ï¼mmï¼
â³Lç´ï¼1395Ã140Ã7.3052Ã1000/(140Ã194333)ï¼52.44ï¼mmï¼
æ以é¢ç»çº¿ä¼¸é¿é为ï¼
5.6904+52.44=58.13=5.813cmã
追é®å¾çº¸ä¸å¹¶æ²¡æè§åº¦åï¼åªææ¢é«ãè·ç¦»ä»ä¹çï¼è½å说æä¸ä¸å
追çé¢ææé å¾ä¸æè§åº¦ã
θ是图纸给的,看清楚是弧度还是角度,计算是用角度的,注意转换。
钢绞线(1)
θ:2.86°=0.04992 K:0.0015 U=0.23 AP=140mm2
EP:194333 R=8m 曲线长:L=θR=0.04992×8=0.399m×2=0.798m
直线长L=(209.9+17.56/2-17.5+100.3+40+15)×2=730.52=7.3052m
根据伸长量计算公式
kx+uθ=0.0015×0.399+0.23×0.04992=0.01208
e-(kx+uθ)=0.98799
PP=1385.762Mpa
△L曲=1385.762×140×0.399×1000/(140×194333)*2=5.6904(mm)
△L直=1395×140×7.3052×1000/(140×194333)=52.44(mm)
所以钢绞线伸长量为:
5.6904+52.44=58.13=5.813cm
弧长是未知的,曲率也未知