Energy absorbing composite tube

An energy absorbing system for absorbing impact energy comprising:

• A) a first impact member;
• B) a second impact member that is mounted to said first impact member;
• C) an energy absorbing composite tube that provides a mount between said first impact member and said second impact member, said energy absorbing composite tube comprising:
• a) a mounting portion comprising a first impact member mounting end that is insertable within a receptacle located in said first impact member, said mounting portion comprising fibers embedded in a resin matrix to form said mounting portion having an outer perimeter;
• b) a main tubular body portion that is integral with said mounting portion, said main tubular body portion comprising an end that is mounted to said second impact member, said main tubular body portion comprising fibers embedded in a resin matrix to form a main tubular body portion having an outer perimeter that is larger than the outer perimeter of said mounting portion to provide a shoulder around the perimeter of said mounting portion where it joins said main tubular body portion;
• and
• D) a delamination wedge located around the perimeter of said mounting portion adjacent to said shoulder, said delamination wedge shaped to provide delamination of said main tubular body portion when said delamination wedge is forced against said shoulder by said first impact member during an impact in which said first and second impact members move towards each other along the longitudinal axis of said composite tube, said delamination of said main tubular body portion providing absorption of said impact energy.

A method for absorbing energy during an impact, said method comprising the steps of:

• A) providing an impact energy absorption system comprising:
• a) a first impact member;
• b) a second impact member that is mounted to said first impact member;
• c) an energy absorbing composite tube that provides a mount between said first impact member and said second impact member, said energy absorbing composite tube comprising:
• 1) a mounting portion comprising a first impact member mounting end that is insertable within a receptacle located in said first impact member, said mounting portion comprising fibers embedded in a resin matrix to form said mounting portion having an outer perimeter;
• 2) a main tubular body portion that is integral with said mounting portion, said main tubular body portion comprising an end that is mounted to said second impact member, said main tubular body portion comprising fibers embedded in a resin matrix to form a main tubular body portion having an outer perimeter that is larger than the outer perimeter of said mounting portion to provide a shoulder around the perimeter of said mounting portion where it joins said main tubular body portion;
• and
• d) a delamination wedge located around the perimeter of said mounting portion adjacent to said shoulder, said delamination wedge shaped to provide delamination of said main tubular body portion when said delamination wedge is forced against said shoulder by said first impact member during an impact in which said first and second impact members move towards each other along the longitudinal axis of said composite tube, said delamination of said main tubular body portion providing absorption of said impact energy;
• and
• B) impacting said second impact member with a force having sufficient impact energy along the longitudinal axis of said composite tube to provide delamination of said main tubular body portion and absorption of at least a portion of said impact energy.

A method for making an energy absorbing composite tube for use in mounting a first impact member to a second impact member, said method comprising the steps of:

• A) forming a composite tube having a longitudinal axis, said composite tube comprising:
• a) a mounting portion comprising a first impact member mounting end that is insertable within a receptacle located in said first impact member, said mounting portion comprising fibers embedded in a resin matrix to form said mounting portion having an outer perimeter;
• b) a main tubular body portion that is integral with said mounting portion, said main tubular body portion comprising an end that is mountable to said second impact member, said main tubular body portion comprising fibers embedded in a resin matrix to form a main tubular body portion having an outer perimeter that is larger than the outer perimeter of said mounting portion to provide a shoulder around the perimeter of said mounting portion where it joins said main tubular body portion;
• and
• B) providing a delamination wedge located around the perimeter of said mounting portion adjacent to said shoulder, said delamination wedge shaped to provide delamination of said main tubular body portion when said delamination wedge is forced against said shoulder by said first impact member during an impact in which said first and second impact members move towards each other along the longitudinal axis of said composite tube, said delamination of said main tubular body portion providing absorption of said impact energy.