Most of us are probably well aware that polymeric composites have numerous applications because of the properties they bring to the table with their inherent advantages over metals and other materials – at least most of the time. In many instances, composites are the correct answer if designed, manufactured and used properly. Composites have distinct advantages in many areas when those properties are designed into the ultimate product. The important thing is to utilize composite materials uniqueness to achieve the best designs while capitalizing on their advantages and minimizing any disadvantages along the way.

A number of composite material advantages that we typically focus on are:

However, over the years we have learned that using composites to arrive at structurally efficient parts requires that we design and manufacture composites with sound engineering judgment as our guideline. To that end, M&P engineers over time have acquired a number of “lessons-learned” and “best practices” that are believed to minimize design and manufacturing risks with composite structures. Table 1 defines a number of these for the record.

Table 1. Typical “Best Design Practices” for Composite Structures

Composite joints, whether (a) bonded, (b) bolted or (c) both bonded and bolted, also have documented lessons that have been learned over the years. Table 2 lists several of those as well.

Table 2. Typical “Best Design Practices” for Joining Composites

Not covered in this series are the aspects pertaining to various bonded joint design options: single-lap shear, double-lap shear, scarfed joints, etc. These will be covered at another time along with a discussion on surface preparation aspects.