The effect of torsional load was discussed in the load
analysis section, and was pointed out that it has no
effect on the stress range of the critical location. The von
Mises stress at location number 2 shown in Figure 9
remains the same with and without considering torsional
load. This is due to the location of the critical point which
is not influenced by torsion since it is located on the
crankpin bearing. Other locations such as 1, 6, and 7 in
Figure 8 experience the torsional load. Figure 12 shows
changes in minimum, maximum, mean, and range of
von Mises stress at location 7 with considering torsion
and without considering it during service life at two
different engine speeds. It can be seen that the
minimum von Mises stress does not change since the
minimum happens at a time when the torsional load is
zero. The effect of torsion is about 16 percent increase
in the stress range at this location.