Patent ID: 7231743

Claim:
A buckling restrained brace ( 1 ) comprising a steel-made center axial member ( 3 ) passed through a buckling-constraining concrete member ( 2 ) comprising buckling-constraining concrete reinforced with a steel member; said buckling-constraining concrete member ( 2 ) having a longitudinal length in an axial direction thereof and a first end and an opposite second end; said steel-made center axial member ( 3 ) comprising a core plate having a longitudinal length in an axial direction thereof and a first end and an opposite second end, wherein the longitudinal length of said core plate of said steel-made center axial member ( 3 ) is longer than the longitudinal length of said buckling-constraining concrete member ( 2 ); said core plate of said steel-made center axial member ( 3 ) has a first cross-sectional area which is (a) located extending axially between said first end of said core plate and said first end of said buckling-constraining concrete member ( 2 ) and (b) located extending axially between said opposite second end of said core plate and said opposite second end of said buckling-constraining concrete member ( 2 ); said core plate of said steel-made center axial member ( 3 ) has a second cross-sectional area at a center portion ( 21 ) located extending axially within said buckling-constraining concrete member ( 2 ) between said first end and said opposite second end of said buckling-constraining concrete member ( 2 ), said core plate center portion ( 21 ) having a first end and an opposite second end; said core plate of said steel-made center axial member ( 3 ) having a third cross-sectional area which is (a) located extending axially between said first end of said center portion ( 21 ) of said core plate and said first end of said buckling-constraining concrete member ( 2 ) and (b) located extending axially between said second opposite end of said center portion ( 21 ) of said core plate and said opposite second end of said buckling-constraining concrete member ( 2 ); wherein said first cross-sectional area of said core plate is larger than said third cross-sectional area of said core plate and said second cross-sectional area of said core plate is smaller than said third cross-sectional area of said core plate.