Реферат: Balsawood Structure Design Essay Research Paper 1

Load was applied evenly along the horizontal section of the joint,

creating a moment and vertical force at the joint. Failure was

determined to occur when the joint either snapped or would not hold any

more load. Each joint?s performance was rated in accordance with the

maximum load it held.

Table 5: Joint Testing Results

Joint Type Load Performance Results of Test

6-a good glue peeled off

6-b better reinforcement crushed

6-c best joint crushed

The scarf joint held the most load, and therefore was rated as best.

This may be because the scarf joint has the highest amount of surface

area that is glued. Therefore requiring more glue and reinforcing the

joint more. In general joint construction this should be kept in mind,

while not all joints will occur at 90 degree angles, it should be noted

that there was a definite relationship between surface area glued and

strength of joint. Discussed in the design section are special self

forming joints that occur only under load, these special type of joints

should be kept in mind for the design as well.

5. Design Concept

Among issues not previously discussed in this report is the effect of

baking the structure. Since balsa, like most woods, is high in water

content, and the goal of this project is to win a weight versus load

carrying capacity competition, the effects of baking out some of the

water were tested. It was apparent that a decent percentage of the

design?s weight could be removed using this method without seriously

effecting the strength of the material.

Another issue to consider is the appearance of “self forming” joints

during testing. Often a vertical piece of balsa would bite in to a