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Abstract
Previous work has shown that by using round mortise and tenon joints, durable maintenance-free school chairs and desks can be produced from largely waste local woody materials by cottage industries in remote regions of the world. Results of this previous work would suggest that by using this same method of construction, well-designed, durable, functional bookcases also could be produced from locally available small-diameter tree species and thin plywood or other thin panel materials. A number of panel and frame bookcases utilizing round mortise and tenon joints were constructed to evaluate their performance. Tests conducted on the resulting bookcase frames and shelves indicated that shelves constructed of thin plywood supported by small front and back shelf rails with ends joined to the cornerposts with round mortise and tenon joints easily met critical shelf deflection criteria. The excellent deflection characteristics of the shelves were credited to the high degree of end fixity of the shelf rails that was obtained through the use of snug fitting round mortise and tenon joints.
In the underdeveloped and developing countries of the world, school furniture represents a large percentage of limited educational budgets. Yet much of the furniture tends to be of low quality and poorly designed structurally so that it has a short service life. Recyclable and renewable resources exist in those countries, however, that can be used in the production of affordable low-cost furniture. Specifically, in the case of bookcases, well-designed, durable, functional furniture can be produced from locally available small-diameter tree species and thin plywood or other thin panel materials. Such furniture can be used in libraries, governmental offices, and in homes, in addition to schools.
Studies in related areas (Haviarova et al. 2001a,b) indicated that round mortise and tenon joints may be used to construct strong durable school chairs and desk frames from small-diameter timber. Further, these studies showed that high quality round tenons can be machined with simple jigs and low-cost equipment. Complementary research (Eckelman et al. 2001) has shown that round mortise and tenon joints are efficient load carriers in bending and highly resistant to cyclic loading.
Round mortise and tenon joint construction provides the means for producing strong durable bookcase frames from locally available wood, wood residues, or semi-processed woody materials. In...