398
CHAPTER 20
MACHINE FRAMES, BOLTED CONNECTIONS
AND WELDED JOINTS
ͳǤ ǡͷǡ͵Ͳ͹
ଵଶ଴଴଴lb
ܣ
௦ൌߨܦଶȀͶ ׷ ܦ ൌ ඥͶܣ௦Ȁߨ ൌඥͶሺͲǤʹͶͲሻȀߨ ൌͲǤͷͷ
Usefive9/16Ǧ12UNCbolts,1¾inlong
ʹǤ ǢͶ
ܨൌͶ
ሺ͹ͷͲሻൌ͵ͲͲͲൌ
͵ǤͶ
 ǣܨଵൌ ͷͳͻ͸ȀͶ ൌ ͳʹͻͻȀ
 ǣܨଶൌ͵ͲͲͲȀͶൌ͹ͷͲ
ܯ ൌሺͷͳͻ͸ሻሺͳ͵ሻൌ͸͹ͷͶͺή
Figure
P20-1
399
ߑݎ
ଶൌͶݎଶൌͶሺͳǤͺͲ݅݊ሻଶൌ ͳ͵ǤͲn2
ܨ
௜ൌெ௥೔
ఀ௥మൌሺ଺଻ହସ଼୪ୠή୧୬ሻሺଵǤ଼଴୧୬ሻ
ଵଷǤ଴୧୬మൌͻ͵ͷ͵Ȁ
Forces on bolt at upper left:
FR= 3041 lb
continued
on following
page.
ܨ௩ൌʹͲͷͶ൅ͳͺͺ ൌ ʹʹͶʹ
ܨோൌξʹʹͶʹଶ൅ʹͲͷͶଶൌ͵ͲͶͳ
ͷǤ ͸ǡ͵Ͳ͹ǡͳͶͲͲȀ
ǣଵସ଴଴lb
଺ൌʹ͵͵Ȁ
ܨ ൌͳʹͻ͸ȋFvFhȌ
AsαFȀWα ଵଶଽ଺୪ୠ
ଵ଴଴଴଴୪ୠȀ୧୬మαͲǤͳ͵ͲଶαߨܦଶȀͶ
ܦൌටସ஺ೞ
Tapere
d
washer
Top
view
Figure P20-
5
͸Ǥ ʹͲͲͲ
ܨ௖ܿ݋ݏʹͷιൌʹͲͲͲlb ൌܨ
௖௩
 Ǣͺǡrα͵ǤͲͲǢ͵ʹͷ
ଶൌͺሺ͵ǤͲ݅݊ሻଶൌ ͹ʹn2
ఛ೏ൌଶ଻ହଷ୪ୠ
ଵ଻ହ଴଴୪ୠȀ୧୬మൌͲǤͳͷ͹n2ൌߨܦଶȀͶ
ܦൌߨൌ
ඥͶሺͲǤͳͷ͹݅݊ଶሻȀߨ ൌ ͲǤͶͶͺ
Useeight½Ǧ13Bolts

ʹͲǦ͸
Moment about center of bolt
WeldedJoints
͹Ǥ ʹͲǦͳǣǢ݂ ൌܸȀܣ௪ǢVαͳʹͲͲͲ
 ǡͶǤͲǣܣ௪ൌʹሺͶሻൌͺǤͲ
௏
ͺǤ ͶȂǡVαͳͷͲͲ
ͻǤ ʹͲǦͷǣʹǤͲͲǤǤ
 Ǥ
ܬ
௪ൌ௕యାଷ௕ௗమ
଺ൌሺଶሻయାଷሺଶሻሺ଼ሻమ
଺ൌ͸ͷǤ͵ଷ
݂
ଵൌ௏
஺ೢൌଵସ଴଴௟௕
ସǤ଴଴௜௡ ൌ͵ͷͲ௟௕
௜௡՝
 ͸Ͳ
݂
ଶൌൌʹͲͲͲȀʹͲൌͳͲͲȀ՝
Case 3 –
Figure 20-8
2
b =
771
lb/in
404
݂
ସൌൌ்஼೓
௃ೢൌ݂
ଷൌͶͷͲ୪ୠ
୧୬
ׇǣ
݂
ଵൌൌ௏
஺ೢൌସଶ଴଴௟௕
ଶଶǤ଴௜௡ ൌͳͻͳ௟௕
௜௡՝
݂
ଵ൅݂
ସൌͳͻͳ൅ʹͲͻ ൌ ͶͲͲȀ
α݂
்ൌඥ݂ଶଶ൅݂
ଷଶ൅ሺ݂ଵ൅݂
ସሻଶൌξͶͲͷ͸ଶ൅ʹͳ͵ଶ൅ͶͲͲଶ
݂
௧ൌͶͲͺͳȀ ͹Ͳ
ݓൌ
ସ଴଼ଵ
ଵଵଶ଴଴ ൌͲǤ͵͸ͶǢUse3/8in=w
497
405
ͳʹǤ ʹͲǦͳͳǢܲଶൌͲǢ
݂
ଵൌൌ௏
஺ೢൌଷ଴଴଴୪ୠ
ଶଶǤ଴୧୬ ൌͳ͵͸௟௕
௜௡՝
ͳ͵Ǥ ʹͲǦͳ PαͶͲͲͲǢ͸Ͳ͸ͳ
 ȂͳͻǦʹ
߬ൌ
௉
஺ೞൌ௉
଴Ǥ଻଴଻௪௅  ൌݐ
ͳͶǤʹͲǦͳͶ ǡ͸Ͳ͸ͳǡͶͲͶ͵
ͳͷǤʹͲǦͳͷ ǡ͸Ͳ͸͵ǡͶͲͶ͵
406
ܮൌ ௉
଴Ǥ଻଴଻௪ఛಲ೗೗೚ೢ ൌ ଼଴଴୪ୠ
ሺ଴Ǥ଻଴଻ሻሺ଴Ǥଵ଼଼୧୬ሻሺହ଴଴଴ౢౘ
౟౤మሻൌͳǤʹͲ
 ͳǤʹͲǤ
ͳ͸Ǥ ʹͲǦͳ͸ ǡ͵ͲͲ͵ǡͶͲͶ͵
 ͳͶǣ
௉
ͳ͹Ǥ 
FαͶͺͲͲǢNαʹǢߪௗൌݏ
௬Ȁʹ
ܣ ൌ ܨȀߪௗǢܦ ൌ ඥͶܣȀߨ
 
