FORMULAE:

Centroid

Bolts and Fasteners

Power screw:

raise lower

collar

positive torque

efficiency

Torque require for preload generation: T = KFid

Static load factor: or if guarding against joint separation

Fp = AtSp

Fatigue loading:

Safety factor: fatigue failure or yielding

Shearing:

=

++++++++

=

n

i

n

ii

A

xA

AAAAAxAxAxAxAxAx

1

1

54321

55443312211

=

n

i

n

ii

A

yAy

1

1

...rrrrMF

CBA

n"n +++= 222

1

nV'F =

tt

iba A

CPA

FF22

=

=t

i

tt

iam A

FA

CPAF

+=+=2

a

aSn

=am

y

max

y SSn +

==

+=

Ld)dL(

2FdT

m

mm

+

=Ld

)Ld(2

FdTm

mm

tanorLdm >>

2dFT ccc

=

T2FL

TTe 0

==

( )( )[ ]cm .sectansectan

dd

6250

12+

+

CPFAS

n itp

= )C(PFn i

=1

Welding

Butt weld: tension shear

Fillet weld in shear: (safety factor)

Welding - torsion: J = 0.707hJu

Welding - bending: I = 0.707hIu

(safety factor)

Spring

Compression spring:

Deflection:

Extension spring:

AV' =

JMr'' =

AV' =

IMc

==

ysysy S.Swhere

Sn 5770==

3

8dFDK

=C

CKs 212 +

=3424

+

=CCK B

NDGdk 3

4

8=

[ ]23416dd

D)K(F AA += 3

8dFD)K( BB

=

drC

CC)K(

drC

)C(CCC)K(

B

A

22

2

2

11

11

12

1

24414

214

14

=

=

=

=

)dN 1 - (2C 1)d (N d)- 2(D L bb0 +=++=

==

alloys nonferrous and steel stainless austenitic 350

steelalloy low and carbon temperedand hardened 500

steelcarbon drawn -cold450

ut

ut

ut

allsy

S.

S.

S.

S

hlF

=hlF

=

hlF.

hl.F 4141

7070==

ys.n

50=

Critical deflection: (for steel)

Fatigue loading:

Critical frequency:

Maximum tensile strength:

Yield strength:

Bearing

Roller contact bearings:

a = 3 for ball bearings

10/3 for roller bearings

for roller bearings

Equivalent radial force:

roller bearings

[ ]21

0 22 /

EG)GE(DL

+