简介：Underharmonicwaveexcitation,thedynamicresponseofabilinearSDOFsystemcanbeexpressedbytheHilbertspectrum.TheHilbertspectrumcanbeformulatedby(1)theinter-wavecombinationmechanismbetweenthesteadyresponseandthetransientresponsewhenthesystembehaveslinearly,or(2)theintra-wavemodulationmechanismembeddedinoneintrinsicmodefunction(IMF)componentwhenthesystembehavesnonlinearly.ThetemporalvariationoftheinstantaneousfrequencyoftheIMFcomponentisconsistentwiththesystemnonlinearbehaviorofyieldingandunloading.Asathoroughstudyofthisfundamentalstructuraldynamicsproblem,thisarticleinvestigatestheinfluenceoftheamplitudeoftheharmonicwaveexcitationontheHilbertspectrumandtheintrinsicoscillatorymodeofthedynamicresponseofabilinearSDOFsystem.