After receiving his Ph.D., Phoenix worked for two years as a senior research associate at Fabric Research Laboratories, in Dedham, MA, before joining the Cornell faculty in 1974. In 1983, Phoenix received the Fiber Society Award for Distinguished Achievement in Basic or Applied Fiber Science, and in 1992 he won the American Society for Testing and Materials' Harold DeWitt Smith Award. In 2005, he won the NASA NESC Engineering Excellence Award for his pressure vessel work in support of the Shuttle's Return to Flight. Recently he has turned his attention to modeling ballistic impact and resistance of soft body armor worn by police and other security personnel.