Moment-Distribution Constants from Cardboard Analogs

An experimental method of determining moment-distribution and slope-deflection constants for beams with variable moments of inertia is proposed. Simple graphics, especially evolved for the purpose at hand, are used to lay out cardboard templates whose ordinates, areas, and their centroidal distances represent significant parameters of the constants sought. Template areas are evaluated and their centroids are located experimentally. This is equivalent, respectively, to numerical integration and division of one integrated function by another. Thus, the experimental part of the method serves as a mechanical analog. The method is simple, rapid, and sufficiently accurate for office use.