A discussion meeting on "Tensile Test Methods for Wire Rope Slings" was held in Shanghai

On July 3, 2013, a drafting discussion meeting for the "Tensile Test Method for Wire Rope Slings" was held in Shanghai.

This standard specifies the terms and definitions of tensile testing for wire rope slings, the apparatus for tensile testing, the preparation of specimens, test methods, test procedures, determination of test validity and test reports, etc. This standard is applicable to the static tensile test and dynamic tensile test of wire rope slings.
1. The static tensile test of the rigging is specified. For the sleeve compression rigging composed of the retractable or the coiled type, the applied force should be transmitted to the specimen through the cylindrical pin. The diameter of the cylindrical pin should be selected to ensure that the conical Angle of the flexible sleeve rigging is between 25° and 35°.

For the sleeve compression ring rigging, the diameter of the cylindrical pin shall not be less than four times the nominal diameter of the wire rope. If necessary, wire rope loops can be used. The pressing sleeve part should be at the middle position of the cylindrical pin.

For the sleeve pressing rigging, after applying 50% of the minimum breaking force of the wire rope to the sample, the remaining force should be applied at a rate not exceeding 0.5% of the minimum breaking force of the wire rope per second. Or after smoothly applying 70% of the minimum breaking force of the steel wire rope to the sample, the remaining force should be applied at a rate not exceeding 10Mpa per second.
2. Dynamic tensile testing of rigging

The fatigue test environment temperature for general wire rope slings is 10℃ to 40℃. The test frequency should not exceed 5Hz.

Except for special requirements, the fatigue test loading method for general wire rope slings is: asymmetric tensile, that is, applying a cyclic tension of 15% to 30% of the minimum breaking force of the wire rope along the axial direction of the wire rope.

The fatigue test loading method for pressed ring rigging and wire rope braided rigging rings is as follows: Apply a cyclic tension of 30% to 60% of the minimum breaking force of the wire rope along the fixed axial direction of the ring rigging.

The fatigue test loading method for clamp-type wire rope slings is to apply a cyclic tension of 15% to 30% of the minimum breaking force of the wire rope along the axial direction. When the tensile force reaches 20% at the beginning of the test, the rope clamp can be tightened again. When the test subject is only the chuck, more than one steel wire rope can be used to achieve 20,000 stress cycles.

The fatigue test loading method for wedge-shaped sleeve fixed wire rope slings is to apply a cyclic tension of 15% to 30% of the minimum breaking force of the wire rope along the axial direction. When the test subject is only a wedge sleeve, more than one steel wire rope can be used to achieve 75,000 stress cycles.

When there are other special requirements for the fatigue test load of wire rope slings, they shall be determined separately by both the supplier and the buyer.
 
Fatigue stress cycle curve
The requirement for the number of fatigue tests is:
The fatigue stress cycle number of the casing compression rigging is 75,000 times.
The fatigue stress cycle number of the rigging for casting the cable section is 75,000 times.
c. The fatigue stress cycle number of the clamping type wire rope rigging is 20,000 times.
The fatigue stress cycle number of the braided rigging is 20,000 times.
The fatigue stress cycle number of the wedge-shaped sleeve fixed wire rope rigging is 75,000 times.
The fatigue stress cycle number of the steel column joint consolidation type rigging is 75,000 times.
When there are other special requirements for the number of stress cycles in the fatigue test of wire rope slings, they shall be determined separately by both the supplier and the buyer.

The participants of this meeting included Kunshan Dong 'an Marine Engineering Co., Ltd. and other units. The deputy general manager of Wance Shanghai Wance Test Equipment Co., Ltd. also attended this meeting.