Calculation of Plastic Hinge and Plastic Moment Capacity Plastic hinge capacity refers to the maximum bending moment that a plastic hinge can withstand b...
Plastic hinge capacity refers to the maximum bending moment that a plastic hinge can withstand before experiencing permanent deformation.
Plastic moment capacity represents the maximum bending moment at which plastic deformation becomes significant, resulting in a permanent deformation beyond the hinge's original shape.
Calculation of plastic hinge capacity:
Determine the yield strength of the hinge material. This represents the maximum bending moment at which the hinge can deform without experiencing plastic deformation.
Calculate the ultimate tensile strength of the material. This represents the maximum bending moment at which the hinge can deform completely without breaking.
Subtract the yield strength from the ultimate tensile strength to obtain the plastic hinge capacity.
Calculation of plastic moment capacity:
Determine the geometric properties of the hinge, including its length, width, and thickness.
Calculate the shear modulus of the material at the desired operating temperature.
Determine the plastic strain required to achieve the plastic hinge capacity. This can be calculated using material properties and the plastic deformation equation.
Calculate the plastic moment capacity as the product of the shear modulus, the plastic strain, and the area of the hinge cross-section.
Example:
A plastic hinge made of acrylic has a yield strength of 50 MPa and an ultimate tensile strength of 100 MPa.
Plastic hinge capacity = Ultimate tensile strength - Yield strength = 100 MPa - 50 MPa = 50 MPa
Plastic moment capacity = Shear modulus * Plastic strain * Area = 2000 MPa * 0.01 * (0.002)^2 = 20 Nmm
Conclusion:
The plastic hinge capacity and plastic moment capacity are crucial parameters for plastic hinge design and analysis. They provide valuable insights into the behavior and strength of plastic hinges under bending loads