4. What is Punching Shear?
Punching Shear
Punching shear is a type of failure of reinforced
concrete slabs subjected to high localized
forces. In flat slab structures this occurs at
column support points. The failure is due to
shear
The shear stress calculated by dividing the
load on a column by the product of its
perimeter and the thickness of the base or
cap, or by the product of the perimeter taken at
one-half the slab thickness away from the
column and the thickness of the base or cap.
5. Punching shear in concrete slabs is a
problem
Punching shear in concrete slabs is a
serious problem in certain structural
systems, such as flat slabs
9. Bearing stress
• Bearing stress is a compressive stress applied to the
contact surface between two connecting members. This
stress can commonly be found on a pin & hole
connection.
• Like general stress, bearing stress is not evenly uniform
over the cross-sectional area but is generally assumed for
simplicity.
• The average bearing stress is the force pushing against
a structure divided by the area. Exact bearing stress is
more complicated. Experiments have shown that the
bearing stress distribution is more elliptical shaped and
not uniform.
10. Bearing Stress Equation
σavg=P/A
σ avg – Stress (Average)
P – Applied Load
A – Cross-Sectional Area (Preload) Bearing
Stress
Bearing stress is a normal stress, not a
shearing stress.
