초록 ▼

A vibration dampening stiffener beam (10, 10′) is secured to a panel member, such as an electrical circuit board (12) that is supported at opposed ends. The beam (10, 10′) extends across a mid portion of the board (12) whereat displacement of the board caused by vibration is at a maximum. The beam i

A vibration dampening stiffener beam (10, 10′) is secured to a panel member, such as an electrical circuit board (12) that is supported at opposed ends. The beam (10, 10′) extends across a mid portion of the board (12) whereat displacement of the board caused by vibration is at a maximum. The beam is an “I”beam or an inverted “T”beam. It has a mounting flange (22, 22′) which is bonded or otherwise secured to the member (12) which it is to stiffen. An energy absorbing material (30) is placed on the sides of the web (24, 24′) of the beam (10, 10″). This material (30) consists of thin metal constraining layers (32) bonded to each other and to the side surfaces of the web by means of a viscoelastic material (34).

대표청구항 ▼

In combination: a member which in use is caused to vibrate and which has a structural makeup resulting in it wanting to vibrate at a relatively low frequency with a relatively large displacement; a stiffening beam secured to a surface of said member, to span across the member and stiffen the member

In combination: a member which in use is caused to vibrate and which has a structural makeup resulting in it wanting to vibrate at a relatively low frequency with a relatively large displacement; a stiffening beam secured to a surface of said member, to span across the member and stiffen the member and increase its frequency of vibration while at the same time decreasing the displacement of vibration, said beam having at least one side surface extending generally perpendicular to the surface of the member; and a plurality of layers of sheet damping material secured to each other and to said side surface of the stiffening beam by an adhesive material, said layers being attached to said side surface of said beam in a manner so that they are positioned generally perpendicular to the surface of the member, for damping vibration of the member by absorbing member vibrational energy which is transmitted to said stiffening beam from said member when it vibrates.