Embedded Files
Side view of hose being deformed as the clamps press down.
developing a Model
developing a Model
The force required to clamp a fire hose is related to both the internal water pressure as well as the magnitude of the deformation of the hose. During the action of clamping the hose the force required can be related to internal water pressure and the stresses present in the hose itself. The model below depicts the force body diagram developed during this project.
The clamp force is simply the force applied to the fire hose by the clamp.
Water pressure force is the reaction force applied to the area of the clamp that is in contact with the hose. The area is estimated as the arc length of a circle related to he depth that the clamp has deformed the hose on a single side.
The force from the the longitudinal internal hose stress is another reaction force that can be related to theta, the angle at which the hose is deformed at the edge of the clamp relative to the horizon. This reaction force is present on each side of the clamp jaw. Only the y-component of this force is taken into account.
Free body diagram of hose deformation from the clamp.
Equations
Equations
Variables
Variables
Testing the model at low Pressure
Testing the model at low Pressure
L1
L2
L3
L4
L5
L6
L7
L8
L9
L10
A comparison of the measured and modeled clamping force for clamping a fire hose at 52 psi.
Testing The MOdel At High Pressure
Testing The MOdel At High Pressure
H1
H2
H3
H4
H5
H6
H7
A comparison of the measured and modeled clamping force for clamping a fire hose at 100 psi.
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