Research Progress Report 274 February, 1967
Furniture Mechanics: The Analysis of Paneled Case And Carcass Furniture
Carl A. Eckelman, Department of Forestry and Conservation
At first glance, an analysis of box, case, and carcass furniture appears almost precluded by the seemingly endless variety of structural types encompassed. A closer examination, however, reveals that drawers, cabinets, wardrobes, chests, and so on usually contain only two basic components - a frame and panels. In some instances the frame may be entirely lacking and the furniture made up entirely of panels, whereas in other furniture the panels may either be absent or structurally inoperative. The greater part of case and carcass furniture, however, contains both a frame and panels. These interact to some degree as a composite structure and are thus structurally indeterminate. An exact analysis of composite structures is quite complex as evidenced by the difficulties, for example, in analyzing a high rise office building (Benjamin, 1958) once walls, partitions, floors, and roof have been added to the basic skeletal framework. To attempt an exact analysis of frame and panel furniture at this time is not justified -first, because of the complexity of the analysis, and second and more important because so little is known about the elastic behavior of this type furniture. The number of assumptions that must be made to analyze internal forces would render the analysis
meaningless when applied to the real structure. Certain types of frame and panel construction can be analyzed, however.

When a complete structural framework is clearly evident, it is often possible to treat the piece as a rigid frame (Eckelman, 1966a, b, c). Even though almost all case and carcass furniture has a thin plywood, masonite, or hardboard back securely attached to the frame, these boards often have little torsional resistance, and their only effect may be to prevent joint rotations and frame translation in the plane of the board. Also, these panels may work loose because of shrinking and swelling accompanying climatic changes or because of severe racking of the case so that the panel can become inoperative. In either event the effect of the back panel on the frame can readily be taken into account. Framed panels may also have little effect on the frame. Frequently, the edges of the central panel are waxed (Feirer, 1963) before assembly so that the panel has some freedom of movement. In furniture constructed of such panels the central panel by itself has little or no effect on the elastic behavior of the furniture although the stiles and rails surrounding it usually are an integral part of the case frame. In other
PURDUE UNIVERSITY • Agricultural Experiment Station • Lafayette, Indiana