For battened compression members (battened struts), by what percentage is the effective length customarily increased to account for shear deformation and additional flexibility?

Introduction / Context:
Battened columns possess discrete batten plates that connect component elements. Compared to laced systems, battened members exhibit additional shear deformation and reduced stiffness. To reflect this in buckling checks, design practice increases the effective length by a fixed percentage for battened members.

Given Data / Assumptions:

• Member type: battened strut/column.
• Requirement: percentage increase in effective length for design.
• Reason: allowance for shear lag/deformation between components due to battening.

Concept / Approach:
Because battened systems are less efficient in shear transfer than continuous lacing, a conservative increase in the effective length factor is applied. Traditional rules specify an increment of 10% for battened members, whereas laced members often use smaller increments.

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