Energy absorber

An energy absorber comprising:

• a pair of shear dampers mounted back to back along a common axis, each said damper comprising a pair of rigid end plates, a laminated structure of rigid plates able to slide past one another and a core of plastically deformable material in a bore through said rigid plates from the inner face of one end of said end plate to the inner face of the other said end plate,
• means to urge said end plates toward one another to maintain each said core at a hydrostatic pressure at least approaching the shear yield stress of said plastically deformable material,
• the two end plates at the distal ends of said pair of dampers being commonly attachable to a first portion of a structure,
• the two dampers having a common end plate at their adjacent ends, said common end plate being attachable to a second portion of a structure,
• the average cross-sectional area of the core in each said damper being from about 5% to about 95% of the average total cross-sectional area of each said damper,
• the arrangement and construction being such that in use said energy absorber, when attached to a first and second structure or portions of a structure, dampens relative motion therebetween.