In　this　paper,　we　present　a　piezoelectric　metamaterial　integrated　with　bistable　circuits　to　realize　adaptive　nonreciprocal　elastic　wave　transmission.　Dynamics　of　the　bistable　circuit　and　the　piezoelectric　metamaterial　are　investigated　numerically　to　analyze　the　wave　transmission　characteristics　of　the　proposed　system.　Results　reveal　that　when　the　excitation　amplitude　exceeds　certain　threshold,　wave　energy　is　able　to　propagate　even　with　excitation　frequency　inside　the　local-resonance　bandgap　of　the　piezoelectric　metamaterial.　This　bandgap　transmission　phenomenon　is　also　known　as　supratransmission.　It　is　shown　that　by　introducing　spatial　asymmetry,　the　system　could　exhibit　different　supratransmission　thresholds　when　it　is　actuated　in　opposite　directions,　and　hence　there　exists　an　excitation　range　within　which　wave　energy　is　only　able　to　propagate　in　one　direction.　Furthermore,　this　excitation　range　to　facilitate　non-reciprocal　energy　transmission　is　adaptable　by　adjusting　the　stable　equilibria　of　the　bistable　circuits,　which　can　be　conveniently　tuned　utilizing　only　DC　voltage　sources.　Additionally,　it　is　shown　that　by　adjusting　the　stable　equilibria,　the　wave　propagation　direction,　analogous　to　the　forward　direction　of　an　electrical　diode,　can　be　easily　reversed.　Lastly,　in　contrast　to　many　nonlinearity　enabled　non-reciprocal　systems,　the　proposed　system　is　able　to　realize　non-reciprocal　elastic　energy　transmission　with　majority　of　the　transmitted　energy　preserved　at　the　original　input　frequency.　Overall,　these　results　illustrate　a　new　means　of　utilizing　nonlinear　piezoelectric　metamaterial　to　manipulate　elastic　wave　transmission.　Copyright　©　2018　ASME.