常用计算(待补充)

螺栓螺母强度校核计算1.本计算只校核螺栓的抗拉强度，如需计算抗剪切强度需查询相应计算方法。

2.本计算参考标准为GB/T 3098.1-2000 和ASTM A3073.计算方法可以参考上述两份标准文件，或者<Guide to Mechinery's Handbook (28th Edition)>。

内容摘录在本4. 下表B列中黑色字体是需要填写的。

蓝色文字是自动计算的。

黄色填充是几个主要计算结果，但是最终校核的结其他规格螺栓需用应力计算：UNC thread:(ASTM A307)d=5/8inch Nominal diameter, Major diameter15.88n=11threads per inchP=0.090909inch screw pitch P=1/ndp=0.565953inch pitch diameter dp=d-0.649519*Pdm=0.506906inch minor diameter dm=d-1.299038*PAs=0.226003sq in tensile stress area As=pi/4*[(dm+dp)/2]^2 Grade AK=60ksi= 414 MPaF=13560.2lbf tensile stress F=K*AsF=60315.76N 1 lbf=4.448NMetric thread:(male thread)d=16mm Nominal diameter, Major diameterP=2mm screw pitchH= 1.73205MM height of the fundamental thread triangl H=0.866025*Pd1=13.83494mm minor diameter of of external thread d1=d-1.082532*Pd2=14.70097mm pitch diameter of external thread d2=d-0.649515*Pd3=13.54626mm d3=d1-H/6As=156.6685mm2tensile stress area As=pi/4*[(d2+d3)/2]^2 Grade 6.8σb公称=600N/mm2σbmin=600N/mm2F=94001.09N tensile stress F=σbmin*As公制螺栓许用载荷较大。

ASTM A3076. Mechanical Properties6.1 Grades A and B bolts and studs shall conform to the hardness specified in Table 2.6.2 GradeAand B bolts and studs 1½ in. in diameter or less, other than those excepted in 6.4, shall 6.3 Grade A and B bolts and studs larger than 1½ in. in diameter, other than those excepteavailable and shall conform to the requirements for tensile strength specified in Table 3. When equ length of the bolt makes full-size testing impractical, machined specimens shall be tested6.4 Grades A and B bolts and studs less than three diameters in length or bolts with drilled or und7. Dimensions7.1 Unless otherwise specified, threads shall be the Coarse Thread Series as specified in the lates 7.2 Unless otherwise specified, Grade A bolts shall be hex bolts with dimensions as given in the la shall be heavy hex bolts with dimensions as given in the latest issue of ANSI/ASME B18.2.1.7.3 Unless otherwise specified, bolts and studs to be used with nuts or tapped holes which have bee threads before hot-dip or mechanically deposited zinc coating.Guide to Mechinery's Handbook (28th Edition) --------FastenersTORQUE AND TENSION IN FASTENERS(P1435)Calculating Thread Tensile-Stress Area.—The tensile-stress area for Unified threads is based on athe minor diameters for Unified screw threads can be found from the major (nominal) diameter, d, an of the following formulas: the pitch diameter dp = d − 0.649519 × P; the minor diameter dm= d − 1.UNJ threads in accordance with MIL-S-8879 have a tensile thread area that is usually consiThe tensile stress area for Unified screw threads is smaller than this area, so the requirin an equivalent joint. To convert tightening torque for a Unified fastener to the equivalwhere d is the basic thread major diameter, and n is the number of threads per inch.The tensile stress area for metric threads is based on a diameter equivalent to the mean of the pit thread triangle from the external-thread minor diameter. The Japanese Industrial StandardIn Equation (11), As is the stress area of the metric screw thread in mm2; d2 is the pitch diameter d3 = d1 − H/6. Here, d is the nominal bolt diameter; P is the thread pitch; d1 = d − 1.082532× P i of the fundamental thread triangle. Substituting the formulas for d2 and d3 into EquationThe stress area, As, of Unified threads in mm2 is given in JIS B 1082 as:Guide to Mechinery's Handbook (28th Edition) --------THREADS AND THREADINGTable 4a. Coarse-Thread Series, UNC and UNRC - Basic Dimensions (P1750)Table 4b. Fine-Thread Series, UNF and UNRF - Basic Dimensions (P1751)Table 4c. Extra-Fine-Thread Series, UNEF and UNREF - Basic Dimensions (P1752)Constant Pitch Series:Table 5a. 4-Thread Series, 4-UN and 4-UNR -Basic Dimensions (P1753)Table 5b.6-Thread Series, 6-UN and 6-UNR -Basic Dimensions (P1754)Table 5c. 8-Thread Series, 8-UN and 8-UNR -Basic Dimensions (P1755)Table 5d. 12-Thread Series, 12-UN and 12-UNR -Basic Dimensions (P1756)Table 5e. 16-Thread Series, 16-UN and 16-UNR -Basic Dimensions (P1757-1758)Table 5f. 20-Thread Series, 20-UN and 20-UNR -Basic Dimensions (P1758)Table 5g. 28-Thread Series, 28-UN and 28-UNR -Basic Dimensions (P1759)Table 5h. 32-Thread Series, 32-UN and 32-UNR -Basic Dimensions (P1759)>。

内容摘录在本页下方。

但是最终校核的结果在B34单元格，蓝色填充。

ASTM A307Note A:Area calculated from the equation: As=0.7854[D-(0.9743/n)]^2where:As= stress area,D= nominal diameter of bolt, andn= threads per inchNote B: 1 lbf=4.448NNote C:Based on 60 ksi (414MPa)Note D:Based on 60-100 ksi (414-690MPa)xcepted in 6.4, shall be tested full size and shall conform to the requirements for tensile strength specifi cepted in 6.4, shall preferably be tested full size and when equipment of sufficient capacity isin Table 3. When equipment of sufficient capacity for full-size bolt testing is not available, or when the ested and shall conform to the requirements specified in Table 4.s with drilled or undersize heads are not subject to tensile tests.d in the latest issue of ANSI/ASME B1.1, and shall have a Class 2A tolerance.ns as given in the latest issue of ANSI/ASME B18.2.1. Unless otherwise specified, Grade B bolts ASME B18.2.1.holes which have been tapped oversize, in accordance with Specification A 563, shall have Class 2Ahreads is based on a diameter equivalent to the mean of the pitch and minor diameters. The pitch andinal) diameter, d, and the screw pitch, P = 1/n, where n is the number of threads per inch, by user diameter dm= d − 1.299038 × P. The tensile stress area, As, for Unified threads can then be found as foll considered to be at the basic bolt pitch diameter; for these threads,equired tightening torque for UNJ threaded bolts is greater than for an equally stressed Unifiuivalent torque required with a UNJ fastener, use the following relationship:o the mean of the pitch diameter and a diameter obtained by subtracting 1⁄6 the height of the fundamental dard JIS B 1082 (see also ISO 898⁄1) defines the stress area of metric screw threads as follows:is the pitch diameter of the external thread in mm, given by d2 = d − 0.649515 × P; and d3 is defined by= d − 1.082532× P is the minor diameter of the external thread in mm; and H = 0.866025 × P is the height tion (11) results in As = 0.7854(d − 0.9382P)2.GB/T 3098.1-20001.因超拧造成载荷超出保证载荷时，对螺纹直径d≤16mm的8.8级螺栓，则增加了螺母脱2.适用于螺纹直径d≤16mm3.对钢结构用螺栓为12mm4.最小抗拉强度适用于公称长度l≥2.5d的产品，最低硬度适用于长度l<2.5d以及其他不5.对螺栓、螺钉和螺柱的实物进行楔负载试验时，应按σbmin计算。