Civil Engineering Reference
In-Depth Information
For wide-band vibration, Equation (5.64) can be modified, following Equation (5.55),
to:
(5.65)
By setting
D
equal to 1 in Equations (5.64) and (5.65), we can obtain lower and upper
limits to the fatigue life as follows:
(5.66)
(5.67)
5.6.4.1
Example
To enable the calculation of fatigue life of a welded connection at the base of a steel pole
using Equations (5.66) and (5.67), the following values are assumed:
Then from Equation (5.66),
From Equation (5.57),
a=
0.926-0.033
m
=0.761
From Equation (5.56), this is a lower limit for λ
This example illustrates the sensitivity of the estimates of fatigue life to the values of
both
A
and
c
. For example, increasing
A
to 0.15 MPa/(m/s)
2
would decrease the fatigue
