Numerical Investigation of 1 × 7 Steel Wire Strand under Fretting Fatigue Condition

Area of Science:

• Mechanical Engineering
• Materials Science
• Tribology

Background:

• Wire ropes are susceptible to fretting fatigue under combined axial and bending loads.
• Failure in wire ropes often initiates at high localized stresses at the trellis point of contact.
• Previous fatigue life estimations relied on continuum damage mechanics, dependent on localized stress and micro-slippage.

Purpose of the Study:

• To investigate the stress distribution and relative wire displacements in wire ropes under fretting conditions.
• To understand the influence of friction on stress evolution and micro-slippage.
• To validate computational findings with experimental observations of crack initiation.

Main Methods:

• Utilizing a finite element approach to simulate stress and displacement.
• Analyzing radial and axial stress distributions.
• Examining the effects of various loading and frictional conditions.

Main Results:

• Relative wire movements are significantly higher when friction is disregarded.
• In the presence of friction, relative movement is confined to the contact region boundaries.
• Micro-slip occurs due to differential displacements between outer and central wires, consistent with experimental crack initiation sites.

Conclusions:

• Finite element analysis effectively models stress and displacement in wire ropes under fretting fatigue.
• Friction plays a critical role in localizing micro-slippage to contact boundaries, influencing crack initiation.
• This study enhances the understanding of fretting fatigue mechanisms in wire ropes, aiding in life prediction.