Plastic structural element with inserts

Abstract

Inserts of metal in the plastic of a plastic structural element are coated with a coupling layer of fibre-reinforced plastic, which reduces the abrupt change in stiffness and/or coefficient of thermal expansion at the joining interfaces in the metal-plastic composite. By altering the volume fraction of fibres and/or by of different orientation the fibre layers within the coupling layer, a gradual change in the E-modulus and the thermal expansion coefficient are produced, as a result of which abrupt changes in these values at the composite interfaces can be avoided. The sudden change in stiffness between the plastic material and the metal insert is also reduced by reducing the stiffness of the insert, which again is achieved by specific choice of shape. Preferred, in particular, is a finger-shaped fanning out of the insert in the plastic material.

1 - 19 . (canceled).  
   
   
       20 . A plastic structural element, comprising: 
 a fiber reinforced plastic material with a matrix-forming plastic; and    at least one connecting part formed as an insert having a length embedded in the matrix-forming plastic and a length that projects from the fiber reinforced plastic material to form a connecting point for attachment means, the insert exhibiting different values of at least one of elastic modulus and thermal expansion coefficients compared to the fiber reinforced plastic material, the plastic structural element exhibiting the following feature:    the insert having at least one aperture through which at least one of reinforcing fibers, fiber strands and textile type materials are looped and are embedded in and intermittently joined to the plastic matrix of the plastic structural element at its free end so as to anchor the insert in the plastic material.    
   
   
       21 . A plastic structural element, comprising: 
 a fiber reinforced plastic material with a matrix-forming plastic; and    at least one connecting part formed as an insert having a length embedded in the matrix-forming plastic and a length that projects from the fiber reinforced plastic material to form a connecting point for attachment means, the insert exhibiting different values of at least one of elastic modulus and thermal expansion coefficients compared to the fiber reinforced plastic material, the plastic structural element exhibiting the following feature:    the imbedded length of the insert is one of strip-shaped and finger-shaped with a plurality of strips or fingers configured so as to reduce a geometrical movement of inertia of the embedded length, the strips or fingers one of lie parallel, are comb-like and fan-shaped.