this brace assembly 56 non aging alloy compositions are necessary since the service life of the seismic brace is expected to be very long e g 20 50 years in particular 1100 o annealed aluminum is well adapted to serve as the brace strut 50 for the multi armed strut 50 1100 o annealed aluminum shows a material yield strength of approximately 10 ksi and strain to failure well beyond 1 the multi armed strut 50 may be manufactured using extrusion or be welded from strip material while the 1100 o annealed aluminum exhibits the hysteretic properties needed the resultant strut 50 must be reinforced to provide sufficient stiffening to suppress brace buckling at a reasonable weight and cost a reinforcing outer collar described below is well suited to provide the stiffening a sleeve 54 and spacer 52 together form the collar accomplishing the suppression of brace buckling the spacers 52 and sleeve 54 accomplish the buckling resistance as a system when the spacer 52 serves primarily a stress transfer function the sleeve 54 supplies the buckling suppression rigidity when the spacer 52 performs more of the buckling suppression the sleeve 54 may provide less of the buckling suppression rigidity although the full function sleeves may still be used in a first implementation shown in fig4 a structural foam of approximately 20 lb ft 3 density or less is used as.