The Magnetoelastic Contribution to the Steel Internal Damping

Area of Science:

• Solid Mechanics
• Materials Science
• Thermodynamics

Background:

• Internal damping in steel affects its performance in dynamic applications.
• Thermoelastic and magnetoelastic effects contribute to energy dissipation in ferromagnetic materials like steel.
• Understanding these damping mechanisms is crucial for designing reliable steel components.

Purpose of the Study:

• To investigate and quantify the internal damping in steel arising from both thermoelastic and magnetoelastic phenomena.
• To compare the contributions of thermoelastic and magnetoelastic damping under different experimental conditions.
• To analyze the influence of a magnetic field on the damping behavior of steel.

Main Methods:

• Development of a theoretical formulation based on thermodynamical potentials and a hysteretic damping model.
• Experimental investigation of a steel rod under alternating pure shear strain to study thermoelastic damping.
• Introduction of magnetoelastic effects in a steel rod subjected to torsion in a magnetic field, utilizing the Sablik-Jiles model.

Main Results:

• The thermoelastic contribution to damping was analyzed in a configuration focusing on temperature transients.
• The magnetoelastic contribution was investigated in a free-motion torsion test under a magnetic field.
• Quantitative assessment revealed the significant influence of magnetoelastic dissipation, with computed damping coefficients compared to thermoelastic ones.

Conclusions:

• Both thermoelastic and magnetoelastic phenomena play a role in steel's internal damping.
• The magnetoelastic effect can be a prevailing damping mechanism in steel under specific conditions, particularly in the presence of a magnetic field.
• The study provides a quantitative comparison of these damping coefficients, enhancing the understanding of energy dissipation in steel.