Shock Force Calculator

Formula

To calculate the Shock Force (SF):

\[ SF = L \times \left( 1 + \sqrt{1 + \frac{2 \times FD \times A \times E}{L \times LG}} \right) \]

Where:

\(SF\) is the shock force (lbf)
\(L\) is the load (lbf)
\(FD\) is the falling distance (in)
\(A\) is the cross-sectional area of the rope (in^2)
\(E\) is the modulus of elasticity (lbf/in^2)
\(LG\) is the length of the chord (in)

What is a Shock Force?

A shock force is a force seen by a rope attached to a falling object. It is crucial in understanding the impact forces in scenarios such as climbing, rescue operations, and other applications where ropes are used to arrest falls.

Example Calculation 1

Let's assume the following values:

Load (L) = 200 lbf
Falling Distance (FD) = 10 in
Cross-Sectional Area of Rope (A) = 0.5 in^2
Modulus of Elasticity (E) = 30000 lbf/in^2
Length of Chord (LG) = 100 in

Using the formula:

\[ SF = 200 \times \left( 1 + \sqrt{1 + \frac{2 \times 10 \times 0.5 \times 30000}{200 \times 100}} \right) \approx 200 \times (1 + \sqrt{1 + 15}) \approx 200 \times (1 + 4) = 1000 \text{ lbf} \]

The Shock Force is approximately 1000 lbf.

Example Calculation 2

Let's assume the following values:

Load (L) = 150 lbf
Falling Distance (FD) = 5 in
Cross-Sectional Area of Rope (A) = 0.3 in^2
Modulus of Elasticity (E) = 25000 lbf/in^2
Length of Chord (LG) = 80 in

Using the formula:

\[ SF = 150 \times \left( 1 + \sqrt{1 + \frac{2 \times 5 \times 0.3 \times 25000}{150 \times 80}} \right) \approx 150 \times (1 + \sqrt{1 + 12.5}) \approx 150 \times (1 + 3.54) = 680.85 \text{ lbf} \]

The Shock Force is approximately 680.85 lbf.