# Two-Way Shear Strength.

Two-Way shear strength of two-way members is calculated automatically

**İnternational Design Codes**

* ACI 318-19 : *Two-Way Shear Strength

* TSC 2018 : *Punching Shear Stress at Critical Section (7.11.8)

**Notation in ACI 318-19**

* A_{v }= *area of shear reinforcement within spacing s, in.

^{2}

*perimeter of critical section for two-way shear in slabs and footings, in.*

**b**_{o}=*distance from extreme compression fiber to centroid of longitudinal tension reinforcement, in.*

**d =***nominal diameter of bar, wire, or prestressing strand, in.*

**d**_{b}=*specified compressive strength of concrete, psi*

**f**_{c }^{'}_{ }_{ }=

**√f**_{c}‘*square root of specified compressive strength of concrete, psi*

^{ }_{ }=*specified yield strength of transverse reinforcement, psi*

**f**_{yt }_{ }=*stress corresponding to nominal two-way shear strength provided by concrete, psi*

**v**_{c }=*equivalent concrete stress corresponding to nominal two-way shear strength of slab or footing, psi*

**v**_{n }=*equivalent concrete stress corresponding to nominal two-way shear strength provided by reinforcement, psi*

**v**_{s }=*maximum factored two-way shear stress calculated around the perimeter of a given critical section, psi*

**v**_{u }=*= constant used to calculate*

**α**_{s}*V*in slabs and footings

_{c}*ratio of long to short dimensions; clear spans for two-way slabs, sides of column, concentrated load or reaction area; or sides of a footing*

**β =***strength reduction factor*

**ϕ =***= modification factor to reflect the reduced mechanical properties of lightweight concrete relative to normalweight concrete of the same compressive strength*

**λ***= factor used to modify shear strength based on the effects of member depth, commonly reffered to as the size effect factor*

**λ**_{s}Nominal shear strength of the two-way members with and without shear reinforcement is calculated by using *Codes.*

**Critical Sections for Two-way Members**

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