Sanyo SGP-EW120M2G2W Technical Data Manual page 63

System Design
In the diagram above,
G : Position of center-of-gravity of equipment
W : Weight (N) of equipment alone
R : Pull-out force of one mounting bolt (N)
b
n : Total no. of mounting bolts
n : No. of mounting bolts on one side subject to tension
t
by toppling force (in the direction being considered)
h : Height of unit center-of-gravity above mounting
G
surface (mm)
L : Bold span (mm) from direction of concern
(L : End-on direction, L
1
L : Distance from center-of-bolt to center-of-gravity as
G
viewed from direction of concern (but L
Mounting bolt pull-out force
F
・h
H G
R =
b
Mounting bolt shear stress
F
H
τ=
n・A
Table of allowable stress on bolts
Bolt
Bolt diameter
material
40 mm or less
SS400
More than 40 mm
40 mm or less
SUS304
More than 40 mm
Notes
1) The values in the above table are derived from "Steel structure design criteria" published by the
Architects Institute of Japan.
2) Use the value f in the table if necessary to investigate bolt tensile stress.
t
3) Strength of a bolt subject to simultaneous tension and shear can be checked as follows.
a) τ f
s
b) σ ≤ the smaller of f
where, τ : Shear stress on bolt
σ : Tensile stress on bolt (σ = R
f : Allowable stress on bolt with shear stress only (value from above table)
s
f : Allowable stress on bolt with tensile stress only (value from above table)
t
f : Allowable tensile stress on a bolt with simultaneous shear stress, but f
ts
4) The allowable tensile stresses in the above table are evaluated using the cross-sectional area of the
minor diameter of the screw thread. However, when calculating for selection purposes, the
cross-sectional area based upon the nominal diameter may be used.
5) If the threaded portion is subject to shear, then if using the cross-sectional area based upon the nominal
diameter, multiply the value of f
7. Center-of-gravity and earthquake resistance
= Broadside direction)
2
≤ /2 (mm))
G
- (W-F )・L
V G
L・nt
Long-term allowable stress
Tension (f )
t
118
108
137
126
or f , but f = 1.4f
t ts ts t
in the above table by 0.75.
s
F : Design horizontal force (N)
H
(F =K
H H
F : Design vertical force (N)
V
F =
V
A : Nominal cross-sectional area of one
mounting bolt (mm
τ: Shear stress on bolt (N/ mm
f : Allowable tensile stress on a bolt with
ts
simultaneous shear stress (N/ mm
However, f
Mounting bolt tensile stress
δ=
Allowable tensile stress on a bolt with
simultaneous shear stress
f = 1.4f
ts t
Short-term allowable stress
Shear (f ) Tension (f
s
88
80
103
94
– 1.6τ
/A)
b
D-32
・W)
1
F
H
2
2)
2
)
≤ ft
ts
R
b
A
- 1.6τ
Units (N/ mm
) Shear (f )
t s
176 132
162 121
206 154
188 141
≤ f
ts t
2
)
2
)