title: Formulas for Stress and Strain
author:  Raymond J. Roark 
description: The best reference on stress analysis ever published--now bigger and better than ever! Roark's Formulas For Stress and strain, Sixth Edition. Engineers the world over have used Roark's formulas for fast, superior stress analysis in engineering design. The sixth edition has it all--hundreds of valuable formulas and new data on curved beams, shell, and planes areas. It will save you hours of valuable time and money every time you design and analyze the physical and environmental stresses of structural components. With Roark, you don't have to resort to costly and time-consuming numerical analysis. You'll be able to quickly and easily apply formulas for shells, plates, beams, bars, columns, and planes to verify the accuracy and reliability of their design.
zlib_text: CHAPTER
  1
  PROPERTIES OF ENGINEERING
  MATERIALS
  SYMBOLS5;6
  a
  area of cross section, m2 (in2)�
  original area of cross section of test specimen, mm2 (in2)
  Aj
  area of smallest cross section of test specimen under load Fj, m2
  (in2)
  Af
  minimum area of cross section of test specimen at fracture, m2
  (in2)
  A0
  original area of cross section of test specimen, m2 (in2)
  Ar
  percent reduction in area that occurs in standard test
  specimen
  Bhn
  Brinell hardness number
  d
  diameter of indentation, mm
  diameter of test specimen at necking, m (in)
  D
  diameter of steel ball, mm
  E
  modulus of elasticity or Young’s modulus, GPa
  [Mpsi (Mlb/in2)]
  f"
  strain fringe (fri) value, mm/fri (min/fri)
  f�
  stress fringe value, kN/m fri (lbf/in fri)
  F
  load (also with subscripts), kN (lbf)
  G
  modulus of rigidity or torsional or shear modulus, GPa
  (Mpsi)
  HB
  Brinell hardness number
  lf
  ﬁnal length of test specimen at fracture, mm (in)
  lj
  gauge length of test specimen corresponding to load Fj, mm
  (in)
  l0
  original gauge length of test 