TABLE OF CONTENTS | Symbols | |||
| Allowable materials strength in tension | ? tu | Elastic tensile stress concentration factor in infinitely wide plate with unloaded hole | K t |
| Allowable far-field tensile stress | ? u | Elastic isotropic tensile stress concentration factor, with respect to net tension stress | K te |
| Allowable far-field tensile strain | ? u | Effective tensile stress, with respect to net tension stress | K tc |
| Allowable materials strength in shear | ? u | Effective tensile stress concentration factor for loaded hole, with respect to hole diameter | K tbc |
| Through-thickness stress | ? z | Load capacity of joint per unit width | P |
| Allowable materials strength in bearing | ? bgu | Load on joint per unit width | p |
| Tensile stress bypassing hole | ? by | Correlation coefficient between experimental and observed stress concentration factors | C |
| Bearing stress | ? bg | Hole or fastener diameter | d |
| Modulus in load direction | E x | Strip width | w |
| Modulus normal to load direction | E y | Strip thickness | t |
| Shear modulus, in plane | G xy | Edge distance | e |
| Major Poisson ratio | v xy | Stress ratio, minimum/maximum | R |
| Torque | T |
This section describes simple design procedures and materials engineering topics relevant to the application of mechanical joints in composite airframe structures.
Intuitively, it may be concluded that mechanical fastening is an unsatisfactory means of joining composites because the fastener holes must cut fibers, destroying part of the load path. However, although considerable loss in strength occurs (typically to half of the original strength), acceptable joints can be made. Indeed, mechanical fastening...
