CHAPTER XVI. 



STRUCTURAL MECHANICS. 



GENERAL NOMENCLATURE. The following nomenclature will be used for all materials 

 except reinforced concrete, for which a special notation is given. 

 A = area of cross section. 

 / = length or span. 

 L = length or span. 

 b breadth of rectangular section. 

 d depth of section; diameter of rivet. 

 / = thickness of plates, etc. 

 R = radius of circle. 

 D = diameter of circle. 

 h = height of wall. 



c = distance from neutral axis to extreme fiber. 

 A = total deformation in length /, or maximum deflection of beams. 

 5 = unit deformation. 



* = horizontal coordinate of elastic curve; variable. 

 y = vertical coordinate or deflection of elastic curve; variable. 

 e = eccentricity; efficiency. 

 I = moment of inertia. 

 / c = polar moment of inertia. 

 / = product of inertia. 

 S = section modulus. 

 r = radius of gyration. 

 P = pitch of rivets. 



P = concentrated load or total stress in a member. 

 / = unit fiber stress. 

 f e = unit compressive fiber stress. 

 ft = unit tensile fiber stress. 

 / = unit shearing fiber stress. 



W = total uniformly distributed load; weight of a body. 



w = uniformly distributed load per unit of length; load per unit of lengch at a distance 

 unity from left end for a uniformly varying load; unit internal pressure. 



R = reactions at supports. 

 M x = moment at any section. 

 M = maximum moment. 

 V x = total shear on any section. 

 V = maximum total shear. 

 E = modulus of elasticity. 

 G = shearing modulus of elasticity. 

 X = Poisson's ratio. 

 + = compressive stress. 

 = tensile stress. 



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