| 摘要 |
<p>A fastener such as a self piercing rivet (1) is inserted into sheet material (19) without full penetration such that the deformed end of the rivet remains encapsulated by an upset annulus of the sheet material (19). The sheet material (19) is clamped between a nose (17) and a die (16) of a riveting machine. Once the sheet material (19) is clamped, the distance between the nose (17) and the die (16) is controlled during the riveting operation by a restraint device (20, 23). This technique ensures that reaction forces generated in the joint between the nose (17) and the die (16) during riveting are absorbed in the joint as compressive stresses during the riveting operation so that the resulting joint has improved fatigue life. Furthermore, the rivet insertion load imparted into the C frame as a reaction force is applied back into the joint as a post rivet-insertion clamping load. Alternatively, a separate clamping force is applied after the rivet (1) has been inserted.</p> |
