Wire Ropes Under Tensile Load - Wire Ropes: Tension, Endurance, Reliability - page 122

Fig. 2.30 Rotary angle u
and twist angle x of a vertical
hanging wire rope without
rotation protection at the
lower end

x upper ¼ x ð v ¼ L Þ ¼ 1 : 79 rad = m ¼ 103 = m ¼ 164 = 100d :

The calculated twist angles are smaller than the allowed limit 360/

100d (Table 2.6 ).

Results simplified calculation:
With the simplificated calculation the maximum rotary angle is

u max ¼ 232 : 6 rad

and the twist angles are

x lower ¼ x ð v ¼ 0 Þ ¼1 : 98 rad = m and x upper ¼ x ð v ¼ L Þ ¼ 1 : 75 rad = m :

2.4.4.3 Suspended Wire Rope Without Rotation Protection
at the Lower End

At the lower end the wire rope has no rotation protection. However this rope end is
like the upper rope end fixed in a termination so that the relative motion of wires
and the strands are prevented [this is the condition for the validity of the constants
c of the Table 2.6 and all the equations based on Eq. ( 2.77 )]. The rotary angle u
and twist angle x of a vertical hanging wire rope without rotation protection at
lower end is demonstrated in Fig. 2.30 .
With the torque M = 0 the twist angle is (again for S 0 m g L cos b F )
according to ( 2.85 )

c 1 d ð S 0 þ m g x sin b F Þ
c 2 d ð S 0 þ m g x sin b F Þþ c 3 G d 4 :

x ¼ ð 2 : 85a Þ