Pocketbook of Useful Formulæ and Memoranda
for Civil and Mechanical Engineers

167 OF ENGINEERING FORMULÆ. Strains on Lattices. With a distributed load advancing from either point of support. : Let the line A B represent the span; E being the centre. With any convenient scale lay oft BC = the strain on thé end lattices from the moving load evenly distributed, and B D = strain on the end lattices from the fixed load. Join D E with fl straight line and C A with a parabolic line AFC. Then the ordinates measured By the scale from the line D E to the line F C repre- sent the maximum strain at any point from the moving and the fixed loads combined, and the ordinates measured from the line B E to the para- bolic line F C represent the maximum strain at any point due to the moving load alone. The greatest possible strain on the centre lattices is one-fourth of the strain upon the end lattices due to the pioying load alone evenly distributed. ’ '