CHARACTERISTICS OF PLASTIC HINGESCHARACTERISTICS OF PLASTIC HINGES

CHARACTERISTICS OF PLASTIC HINGES

1. Characteristic curves

The general form of a Plastic Zone (PZ) characteristic curve is a non-linear load-deformation relationship measured on structural parts of the vehicle in laboratory tests.

Plastic Hinge characteristic curves are a bending moment (M) - rotational angle () relationship. The general form of a PH characteristic curve is shown in Figure A.8. A.1.1

Figure%20A8

Figure A8. A1.1 - Characteristic curve for a plastic hinge

2. Aspects of deformation ranges

2.1. The "measured range" of the PH characteristic curve is the range of deformation over which measurements have been made. The measured range may contain the fracture, and/or the rapid hardening range. Only values of the PH characteristics which appear in the measured range shall be used in the calculation.

2.2. The "working range" of the PH characteristic curve is the range covered by the calculation.

The working range shall not exceed the measured range, and may contain the fracture, but not the rapid-hardening range.

2.3. The PH characteristics to be used in the calculation shall contain the M- curve in the measured range.

3. Dynamic Characteristics

There are two kinds of PH and PZ characteristics: quasi-static and dynamic. The dynamic characteristics of a PH may be determined in two ways:

3.1. by dynamic impact testing of the component.

3.2. by using a dynamic factor Kd to transform the quasi-static PH characteristics.

This transformation means that the values of the quasi-static bending moment may be increased by Kd.

For steel structural elements Kd = 1.2 may be used without laboratory test.

Figure%20A8

Figure A8.A1. 2 - Derivation of plastic hinge dynamic characteristics from the static curve