| 摘要 |
As ambient conditions change around a truss structure, such as a wooden truss in an attic, webs of the truss are affected by changes of moisture and temperature in the air. As the end-grain of the webs expand and contract, a contraction and expansion management (CEM) joint minimizes unwanted expansion and contraction in the truss chord. An elastic layer such as an elastomer in the CEM joint absorbs expansion while plates around the CEM joint maintain rigidity of the chord, keeping it secure to the walls. As the moisture and temperature in the attic decrease, the end-grain of the truss returns to its original state.
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