Wood Diaphragm Deflections. II: Implementing a Unified Approach for Current CLT and WSP Practice

Acknowledgments

Notation

A

area of a diaphragm chord (in.²);

a

exponential behavior variable of the nail slip term e_n in SDPWS Table C4.2.3D;

b

ratio of edge fastener spacings, $S_{\mathrm{\perp }}/S_{\parallel }$;

E

modulus of elasticity of diaphragm chords (lb_f/in.²);

e_f

fastener slip along a panel edge;

$e_{f\parallel }$

fastener slip along a panel edge parallel to the diaphragm load direction based on shear along the diaphragm boundary;

e_f⊥

fastener slip along a panel edge perpendicular to the diaphragm load direction based on shear along the diaphragm boundary;

e_n

nail slip measured parallel to the nearest panel edge based on shear along the diaphragm boundary (in.);

G_a

apparent diaphragm shear stiffness (kips/in.);

G_vt_v

panel in-plane, through-the-thickness, shear stiffness (lb_f/in. of depth) of WSP panels;

L

length of a diaphragm span, perpendicular to the diaphragm load direction (ft);

$n_{\parallel }$

number of slip planes at panel-to-panel connections parallel to the diaphragm load direction;

n_⊥

number of slip planes at panel-to-panel connections perpendicular to the diaphragm load direction;

$P_{\parallel }$

panel dimension parallel to the diaphragm load direction;

P_⊥

panel dimension perpendicular to the diaphragm load direction;

$S_{\parallel }$

fastener spacing on panel edges parallel to the diaphragm load direction;

S_⊥

fastener spacing on panel edges perpendicular to the diaphragm load direction;

V_f

shear force per fastener;

$V_{f\parallel }$

shear force per fastener on a panel edge parallel to the diaphragm load direction;

V_f⊥

shear force per fastener on a panel edge perpendicular to the diaphragm load direction;

V_n

shear force per nail;

$V_{\parallel }$

total shear on a panel edge parallel to the diaphragm load direction;

V_⊥

total shear on a panel edge perpendicular to the diaphragm load direction;

v

induced shear per unit length typically at the diaphragm boundary/support line (lbs/ft);

W

width of the diaphragm, parallel to the diaphragm load direction (ft);

x

distance from the nearest diaphragm support to the location of interest (ft);

Δ_c

diaphragm chord splice slip at the induced unit shear (in.);

δ_chord

diaphragm deformation component from the chord slip;

δ_dia

diaphragm deformation;

δ_flex

diaphragm deformation component from bending;

δ_shear

diaphragm deformation component from panel shear deformation;

δ_slip

diaphragm deformation component from the panel fastener slip; and

γ

fastener slip stiffness, or slip modulus.

References