The relaxation modulus is represented by the image below.

To compute for relaxation modulus, two essential parameters are needed and these parameters are **Time Dependent Stress (σ _{(t)})** and

**Strain Level (ε**

_{o}).The formula for calculating relaxation modulus:

E_{r(t)} = ^{σ(t)}/_{εo}

Where:

E_{r(t)} = Relaxation Modulus

σ_{(t)} = Time Dependent Stress

ε_{o} = Strain Level

Let’s solve an example;

Find the relaxation modulus when the time dependent stress is 12 and the strain level is 6.

This implies that;

σ_{(t)} = Time Dependent Stress = 12

ε_{o} = Strain Level = 6

E_{r(t)} = ^{12}/_{6}

E_{r(t)} = 2

Therefore, the **relaxation modulus **is **2 Pa.**

**Calculating the Time Dependent Stress when the Relaxation Stress and the Strain Level is Given.**

σ_{(t)} = E_{r(t)} (ε_{o})

Where:

σ_{(t)} = Time Dependent Stress

E_{r(t)} = Relaxation Modulus

ε_{o} = Strain Level

Let’s solve an example;

Find the time dependent stress when the relaxation modulus is 18 and the strain level is 5.

This implies that;

E_{r(t)} = Relaxation Modulus = 18

ε_{o} = Strain Level = 5

σ_{(t)} = E_{r(t)} (ε_{o})

σ_{(t)} = 18 (5)

σ_{(t)} = 90

Therefore, the **time dependent stress **is **90.**

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