2003-08-012024-05-18https://scholars.lib.ntu.edu.tw/handle/123456789/697435摘要：本計畫擬研究開關機制之理論並以實驗驗證， 目的在於應用於彈塑性組成建模中的彈塑兩相切換以及摩擦振動控制的黏滑兩相切換。 擬議中的研究對象以降伏厚面開關機制為主，惟仍探討其他可能性，如橫貫臨界分叉等。 為解決反向載重時應力應變曲線過方，以及循環載重時回應力循環振盪等傳統彈塑性組成律的缺陷， 本計畫擬將降伏面由零厚度增厚為有厚度，以增大塑性相的組成方程式的適用空間， 為彌補因增厚而喪失的一致性條件，降伏厚面必須有異於傳統降伏面的開關機制，我們擬探討其公設體系、層級組織架構、以及切換條件。 在閔氏時空，塑性組成律及乾摩擦定律可用對稱群刻劃而正確無誤地簡化。本計畫擬發展其閔氏時空的識別理論並納入降伏厚面關開機制， 進行實驗觀察、實驗識別、實驗驗證，並應用於結構振動之摩擦控制上。 <br> Abstract: The project is proposed to study theoretically and experimentally mechenism of switching, with the aim of applying to switching between plastic and elastic phases in the problem of elastoplastic constitutive modeling and switching between sliding and sticking in the problem of vibration control by friction. The focus is on the switching mechanism associated with yield thick-surface, but other feasible approaches such as transcritical bifurcation will also be explored. In order to deal with the problems that the models with a conventional yield surface tend to predict a loop of stress-strain curve which is over square in reverse loading and whose back stress is over oscillatory in cyclic loading, we propose to thicken the yield surface so that the plastic-phase constitutive equations can develop their functions in more ample space in stress space. To remedy the loss of the consistency condition due to the thickening, the yield thick-surface must be associated with a switching mechanism different from that associated with the conventional zero-thickness yield surface. Thus we will study the new system of axioms, hierarchy of special cases, and switching conditions. In Minkowski spacetime, both elastoplastic constitutive laws and dry friction laws can be characterized by symmetry groups in much simpler yet exact ways. We will thereby develop specific identification procedures in Minkowski spacetime, taking the yield thick-surface switching mechanism into consideration, testing and verifying them with experiments and observations, and applying the new mechanism to friction control of structural vibration.開關機制降伏厚面模式識別閔氏時空彈塑性摩擦振動。switching mechanismyield thick-surfacemodel identificationMinkowski spacetimeelastoplasticityfrictionvibration.