The bending stress in a beam is inversely proportional to the section modulus.
If you are looking to find alternatives for a cross-section design, it is generally recommended to check both the section modulus and the moment of inertia. The section modulus helps determine the resistance of a beam to bending stress, while the moment of inertia indicates the distribution of an area about a neutral axis. Both parameters are crucial for ensuring the structural integrity and efficiency of the design.
Young's modulus or modulus of elasticity is a property of the material. As in both the wires we have copper material the young's modulus will be the same. It does not get altered with length or area of cross section.
Bending moment is a measure of the internal response in a structural element when an external force is applied perpendicular to the axis of the element, causing it to bend. It is the product of the force applied to the element and the distance from the point of application of the force to a reference point within the element. Bending moment is an important factor in the design of beams and other structural elements to ensure they can withstand the applied loads.
Resistance R =p(L /A)i,e Resistance(R) of a conductor will be directly proportional to its length(L) ==> if the length of the conductor increases its resistance also will increase.i,e Resistance(R) of a conductor is inversely proportional to its cross section area(A) ==> if the Area of the conductor increases its resistance also will decrease.
The resistance of the wire is directly proportional to the length and inversely proportional to the area of cross section. Also it depends on the material of the wire with which it is made. So three factors. Length, area of cross section, material.
Sectional modulus of any section determines the strength of a section, i.e. if two sections made up of same material then the section with higher section moduls will carry higher load as the allowable stress is constant for a given material. in analysis of it is useful in determining the maximum stress value to which the section is subjected when the moment is konwn from the relation f=(M/Z) where f= stress at extreem fibre M= maximum bending moment on section Z= section modulus = (moment of inertia/ distance of extreem fibre from NA)
The relation between bending moment and the second moment of area of the cross-section and the stress at a distance y from the neutral axis is stress=bending moment * y / moment of inertia of the beam cross-section
section modulus is a measure of the strength of a beam. The more the section modulus the more is the strength.
If you are looking to find alternatives for a cross-section design, it is generally recommended to check both the section modulus and the moment of inertia. The section modulus helps determine the resistance of a beam to bending stress, while the moment of inertia indicates the distribution of an area about a neutral axis. Both parameters are crucial for ensuring the structural integrity and efficiency of the design.
Section Modulus is moment of inertia divided by distance from center of gravity to farthest point on the cross-section or I/c. The units of Moment of Inertia is distance^4 so the units of section modulus is distance^3 ( distance cubed ). So if your units are in meters: I/c = (m^4)/(m) = m^3
section modulus of any section is the ratio of the moment of inertia to the distance of extreem fibre from the neutral axis. plastic section modulus is the section modulus when the cross section is subjected to loading such that the whole section is under yield load. numerically it is equal to the pdoduct of the half the cross section area and the distance of center of gravity of tension and compression area from neutral axis
Plastic Section Modulus about the element local y-direction
Torssional section module
I searched for properties of 1" x 3" 11 gauge rectangular steel tubing, but that is an odd size. We will have to calculate the section modulus (excluding corner radius): S = bd^3 - b1d1^3/6d b = 1" d = 3" b1 = 1 - 2x0.091 = 0.818 d1 = 3 - 2x0.091 = 2.818 S = [(1 x 3^3) - (0.818 x 2.818^3)] / (6 x 3) = 0.483 in^3 M (maximum bending moment) = [P (point load) x l (length)] / 4 Solving for P: P = 4M/l M = s x S Where: s (allowable bending stress) = .55 x yield strength of steel To be conservative we will assume that the steel you have is 30,000 psi M = .55 x 30,000 x 0.483 = 7,969 in-lb P = 4 x 7,969 / 72 in = 442#
pi x d3 / 32
Well, darling, the modulus of rupture formula is simply the maximum amount of stress a material can handle before it breaks. It's calculated by dividing the maximum bending moment by the section modulus of the material. So, in a nutshell, it's all about figuring out how much a material can take before it snaps like a twig.
The resisting bending moment is the product of the yield strength (of the beam material) and the section modulus of the beam. The RBM thus combines the material attributes as well as the geometric attributes of the beam and gives a useful metric to compare different beams irrespective of material or sectional geometry.