1. He smiled, his eyes crinkling.

2. He smiled boyishly, crinkling his eyes.

3. Dad's forehead was crinkling into a frown.

4. It's also crinkling the outer corner of the eye, the orbicularis oculi.

5. Synonyms for Crepitation include crepitus, rustle, whisper, rustling, swish, crackle, susurration, swishing, crinkling and susurrus

6. Synonyms for Cockling include ruffling, wrinkling, creasing, puckering, crinkling, crumpling, rumpling, rippling, roughening and pursing

7. The relative longitudinal strain between the strip edge and strip center is very small in the whole deformed zone, which can prevent appearing crinkling and bloating.