Metal beam with asymmetrical section and damage warning function

Abstract

A metal beam with asymmetric section and damage warning function includes a main body; the cross-sectional shape of the main body section defines a neutral axis, and a pressure zone and a tension zone when subjected to a pure bending moment load. Each point of the main body is arranged in a linear relationship with respect to the neutral axis within the elastic range. The cross-sectional shape of the main body section is on both sides of the neutral axis in an asymmetrical arrangement. The section modulus of the pressure zone of the main body section at the maximum bending moment is greater than the section modulus of the tension zone. Before the pressure zone bears a stress reaching the elastic limit to yield and enter plastic deformation, the tension zone has a stress exceeding the elastic limit and yield to enter plastic deformation first, so that the plastic deformation of the yielding tension zone provides a warning about a possibly occurring compressive shear damage of the pressure zone, forming the present invention.

What is claimed is: 
     
         1 . A metal beam with asymmetric section and damage warning function, comprising a main body and a floor deck; a flange on the main body being fixed with the floor deck through a shear stud, so as to form an integral beam; the main body comprising a main body section; the main body section having a cross-sectional shape which defines a neutral axis, and the main body section defining a pressure zone and a tension zone when subjected to a pure bending moment load; each point of the main body being arranged in a linear relationship with respect to the neutral axis within an elastic range; the cross-sectional shape of the main body section being asymmetrically arranged on both sides of the neutral axis; the pressure zone of the main body section at the maximum bending moment of the main body having a section modulus greater than a section modulus of the tension zone; before the pressure zone bears a stress reaching the elastic limit to yield, the tension zone bears a stress exceeding the elastic limit to yield first and enters a plastic deformation, such that the plastic deformation of the tension zone provides a warning about a possibly occurring compressive shear damage of the pressure zone. 
     
     
         2 . The metal beam with asymmetric section and damage warning function of  claim 1 , wherein the two sides of the main body section asymmetrically arranged on two sides of the neutral axis have a same width, but the thicknesses thereof are thicker on one side and thinner on the other side. 
     
     
         3 . The metal beam with asymmetric section and damage warning function of  claim 1 , wherein the two sides of the main body section asymmetrically arranged on two sides of the neutral axis have a same thickness, but the widths thereof are wider on one side and narrower on the other side. 
     
     
         4 . The metal beam with asymmetric section and damage warning function of  claim 1 , wherein the main body is a transverse beam which is supported by a plurality of supports for bearing a load. 
     
     
         5 . The metal beam with asymmetric section and damage warning function of  claim 1 , wherein the main body section is formed in an H shape or a quadrangular shape.