Statics / Shear Center
Shear Center Calculator
Determine shear center location and torsional stiffness for concrete wall systems
Method
The Rigid Floor-Diaphragm Method (Simplified Procedure) calculates the shear center location for concrete wall systems by assuming a rigid floor diaphragm. The method is limited to axis-parallel walls (horizontal or vertical).
Step 0: Determine reference stiffness I_o = (1/12) × t × L₁³ from the first wall.
Step 1–2: For each wall, compute normalized stiffness contributions based on orientation. Horizontal walls contribute to x-direction stiffness; vertical walls to y-direction.
Step 3: Calculate shear center using:x_F = Σ(x_i × α_yi) / Σα_yy_F = Σ(y_i × α_xi) / Σα_x
Step 4: Compute relative torsional stiffness I_z = Σ[α_xi(y_i − y_F)² + α_yi(x_i − x_F)²]
Per EN 1992–1–1 Clause 5.1 (Linear elastic analysis) and Danish National Annex rigid diaphragm procedure.
Input
Output
Draw at least 2 walls on the grid to calculate results.
References
EN 1992-1-1
Design of concrete structures – Part 1–1: General rules and rules for buildings
§ Clause 5.1 — Linear elastic analysis
Danish National Annex
Rigid floor-diaphragm method (simplified procedure)
Applies to axis-parallel concrete walls in multi-storey buildings