Plastic Behavior of Metallic Damping Materials under Cyclical Shear Loading

Area of Science:

• Seismic Engineering
• Materials Science
• Structural Engineering

Background:

• Metallic shear panel dampers (SPDs) are crucial for seismic protection.
• Understanding material behavior under cyclic loading is vital for SPD design.
• Low yield strength steel 160 (LYS160) is a potential candidate for advanced SPDs.

Purpose of the Study:

• To investigate the cyclic performance of LYS160 and conventional steels.
• To compare the fatigue and deformation capacity of LYS160 against traditional materials.
• To elucidate the failure mechanisms influencing SPD performance.

Main Methods:

• Axial and torsional testing of four metallic damping materials, including LYS160.
• Low cycle fatigue tests under repeated large plastic strain (10-30 cycles).
• Scanning electron microscopy (SEM) analysis to determine failure modes.

Main Results:

• LYS160 exhibits underestimated deformation capacity and fatigue performance based on uniaxial tensile tests.
• The dominant failure mode in LYS160 is stable interlaminate slip, unlike the buckling seen in conventional steels.
• SEM data revealed distinct failure mechanisms differentiating LYS160 from conventional metallic damping materials.

Conclusions:

• LYS160 possesses a large deformation capacity attributed to its unique interlaminate slip failure mode.
• This finding challenges traditional assessment methods for LYS160's performance.
• Results provide foundational insights for the lightweight design of seismic shear panel dampers using LYS160.