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Reference.org
Deflection (engineering)
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<p>In <a href="/facts/Structural_engineering/Wj1vpoGh">structural engineering</a>, deflection is the degree to which a part of a long <a href="/facts/Structural_element/BdYjdKrq">structural element</a> (such as <a href="/facts/Beam_(structure)/V9BPDeS8">beam</a>) is <a href="/facts/Deformation_(mechanics)/xK7R59oI">deformed</a> laterally (in the direction transverse to its longitudinal axis) under a <a href="/facts/Structural_load/MAxjDyhc">load</a>. It may be quantified in terms of an angle (<a href="/facts/Angular_displacement/qoqvM9Np">angular displacement</a>) or a distance (linear <a href="/facts/Displacement_(geometry)/jkmEfS3C">displacement</a>). A longitudinal deformation (in the direction of the axis) is called <i><a href="/facts/Elongation_(mechanics)/xK7R59oI">elongation</a></i>. </p><p>The deflection distance of a member under a load can be calculated by <a href="/facts/Integral/V7lyV997">integrating</a> the function that mathematically describes the slope of the deflected shape of the member under that load. Standard formulas exist for the deflection of common <a href="/facts/Beam_(structure)/V9BPDeS8">beam</a> configurations and load cases at discrete locations. Otherwise methods such as <a href="/facts/Virtual_work/fHzjTNGo">virtual work</a>, <a href="/facts/Direct_integration_of_a_beam/KcV85gES">direct integration</a>, <a href="/facts/Castigliano%2527s_method/ou6WWrgb">Castigliano's method</a>, <a href="/facts/Macaulay%2527s_method/932EkpnL">Macaulay's method</a> or the <a href="/facts/Direct_stiffness_method/CLDGUHzu">direct stiffness method</a> are used. The deflection of beam elements is usually calculated on the basis of the <a href="/facts/Euler%25E2%2580%2593Bernoulli_beam_equation/3DyQV9do">Euler–Bernoulli beam equation</a> while that of a plate or shell element is calculated using <a href="/facts/Plate_theory/7bCRFl8F">plate or shell</a> theory. </p><p>An example of the use of deflection in this context is in building construction. Architects and engineers select materials for various applications. </p>