A Combined Exponential-Power-Law Method for Interconversion between Viscoelastic Functions of Polymers and...

Area of Science:

• Materials Science
• Polymer Science
• Mechanical Engineering

Background:

• Viscoelastic behavior of polymers is crucial for long-term mechanical applications.
• Characterizing viscoelasticity traditionally requires separate creep and relaxation tests.
• Existing methods for interconverting creep and relaxation data can be complex.

Purpose of the Study:

• To review methods for interconverting creep compliance and relaxation modulus.
• To introduce a novel, approximate interconversion scheme.
• To demonstrate the accuracy and applicability of the new method.

Main Methods:

• Review of existing time-domain interconversion techniques.
• Development of a new approximate interconversion scheme using Laplace transform and approximated Gamma function.
• Validation using diverse experimental data from scientific literature.

Main Results:

• The relaxation modulus can be accurately derived from creep compliance data.
• The proposed method offers ease of implementation and broad applicability.
• Experimental data confirms the accuracy of the new interconversion scheme.

Conclusions:

• The new method simplifies the determination of viscoelastic properties for polymers.
• It enables obtaining relaxation modulus from less costly creep tests.
• This approach is valuable for modeling polymer behavior under various mechanical loads.