Pocketbook of Useful Formulæ and Memoranda
for Civil and Mechanical Engineers

173 OF ENGINEERING FOBMULÆ. Girders Unkqually Loaded. (Graphic Determination of Stresses.) DIAGKAM OF LOAD. Find the load on each abutment as follows: With loads A, B, and C, the load on the right abutment üA.+ öB-f't'C R- g . and on the left abutment L=(A + B+C) — R. On a vertical line with any convenient scale lay off dis- tances corresponding to the loads on each point of the girder and on each abutment, and draw lines parallel to each member of the girder ; the diagonal lines being drawn to the horizontal line corresponding to the division of load on the abutments. The stresses may then be measured on the Stress Dia grams with the scale ol loads. If the girder be turned upside down, the stresses will remain the same in intensity, but their character will be changed, the positive stresses becoming negative, and the negative positive.