Measurement of Energy Reflection Coefficient Using Stress Waves

TO make clear the reflection characteristics at fillet parts, the energy reflection coefficient from the fillets is measured. The fillet is composed of the same material as the structure. A semiconductor strain gauge is used to detect single stress pulses. Different from the conventional method where the energy reflection coefficient is the summation of the transfer function obtained by the Discrete Fourier Transform, the coefficient is calculated using strain energy measured by changing the duration of a single stress pulse and the curvature of the fillet. The effectiveness of the new method is confirmed by comparing the results obtained by conventional and new methods. RGsumG : Lcs car:~ctCr~stiqucs tlc la r2llcxioli d'une o ~ ~ ~ i c sur un Opaulernenl solit rnesurOrs. L'6p.::1lcrnc111 c\i compose du mCme materiau quc la structure. U~ie jau:r h lil rCsistant serniconducreur ssr ~1tilis6e pour di-teeter I'impulsion dc contrainte. Le coeificicnt dc retlexioli esl c : I I ~ u I C d i r ~ c r ~ ~ n c ~ i t p u I'C~~ergic d d2l'orrtiatloo en change~n~ la duu2e de I'irnpulsion CI la courhure de I'Cpaulement. Cetre mCthodc chr diiiCrentc de la rn6thode co~~vc~~rionnellc ou le coeilicient dc ti-flexion ew ohrenu par somma~ion de la hnctio~i de translert par la tra~lsiormatioo dc Fourier. L'eflicacilt dc la ~iouvclle mCthode est coolirmOe ell cornparant les r&sultats ohtenus par les dcux rnCthodcs.