Technical Guidance and Solutions

Design and analysis guidance and solutions. Technical information about composites and industry solutions.

Design | Technical Guidance & Review

Design | Technical Guidance & Review

1 posts in this category

Are you Balanced or Unbalanced?

Composite Design and Analysis Guidance
Category: Design | Technical Guidance & Review

Balanced verse and Unbalanced Laminate

So how do we know that we have an unbalanced laminate in the first place? Moreover, if you end up with an unbalanced layup, what are the implications? Good questions to have answers to before signing-off on that laminate design.

Firstly, a perfunctory definition is in order regarding a balanced laminate. A designer will need to ensure that for every -α ply there is a +α ply (with the same material and thickness) somewhere within stacking sequence irrespective of location. Examples of balanced laminates are: [0/30/-30/0] or [45/-45/0/0]. An unbalanced laminate is: [0/30/30/0]...notice that the negative 30-degree ply is no longer present. Now maybe you desire an unbalanced laminate or maybe it’s simply unavoidable but in a majority of design cases this layup scheme should be avoided at all costs. Why? Well, perhaps you have already surmised, this layup scheme has adverse implications, one of them significant…the often dreaded and undesirable in-plane extension-shear coupling.

unbalanced  shear  plate  laminate  extension  coupling  balanced

2017-10-15 22:08:48