Shrinkage stresses in bonded plexiglas structures

It is shown by means of photoelasticity that the shrinkage stresses associated with cold polymerization of the adhesive layer in bonded plexiglas structural elements seriously reduce the reliability of the structure. By suitable heat treatment it is possible to reduce the shrinkage stresses by a factor of approximately four without distorting the shape of the element and increase the permissible stresses by a factor of almost three.