Compression First a little more bending - elastic theory The elastic section modulus First and second moments of area Radius of gyration Short compression members - struts and their design based on cross sectional area and strength Long slender members Buckling and length of member - Eulers Buckling Formula Slenderness ratio Design of compression members as an iterative process Elastic theory of bending General sections in elastic bending First moment of area a measure of the distribution of the area of a shape in relationship to an axis used to find the centroid of an object The second moment of area Compression Two types of members are considered Design of short members is simple Similar to a cable we consider cross section area and strength of materials and in addition quality of product and workmanship Buckling and slender columns Unlike short columns where area of cross section and strength are the main factors LENGTH is the significant factor So how do we use this