Formula For Plastic Section Modulus

The plastic section modulus for a rectangular cross section can be determined by multiplying each section half e g the shaded area shown in figure 1 50 by the distance from its centroid to the centroid for the whole section.

Formula for plastic section modulus. Z elastic section modulus in 3 or mm 3. The two terms are related by the yield strength of the material in question f y by m p f y z. The higher the plastic modulus the more reserve strength the beam has after stress induced deformation has begun.

For asymmetrical sections two values are found. The plastic modulus also known as the plastic section modulus is a theoretical tool used in structural engineering to quantify the strength of beams and how those beams deform under stress. The pna is defined as the axis that splits the cross section such that the compression force from the area in compression equals the tension force from the area in tension.

Online rectangle property calculator. To calculate the value of z for a simple symmetrical. The plastic section modulus depends on the location of the plastic neutral axis pna.

The plastic section modulus is similar to the elastic one but defined with the assumption of full plastic yielding of the cross section due to flexural bending. For symmetrical sections the value of z is the same above or below the centroid. To calculate the section modulus the following formula applies.

So for sections with constant yielding stress the area above and below the pna will. Plastic section modulus and elastic section modulus are related by a shape factor which can be denoted by k used for an indication of. Where i moment of inertia y distance from centroid to top or bottom edge of the rectangle.

Calculate the area of a rectangle. Z max and z min. The plastic section modulus is used to calculate the plastic moment m p or full capacity of a cross section.