CAJ | 학술논문

弹条是实现弹条II型扣件功能的主要元件，传统的疲劳分析方法主要从弹条的应力、应变入手，这并不能反映真实情况，因为弹条在工作中与其它构件接触面表面之间存在微小的相互移动，即微动。应用非线性接触理论，采用库仑摩擦模型模拟弹条与周围接触元件之间的摩擦接触情况，计算出弹条各点的剪切应力τ、相对位移δ及二者乘积τ·δ的值；并采用离散裂缝模型来模拟扣件裂纹的生成及扩展。理论分析表明，若微动磨损在弹条疲劳断裂过程中起主要作用，则断口处应位于弹条中τ·δ值最大的点附件。扣件疲劳试验表明，弹条断口处位于弹条尾部与轨距挡板接触处，处于τ及τ·δ最大的点之间且更靠近τ·δ值最大的点。弹条尾部与轨距挡板之间由于微动磨损产生裂纹，形成污染源，反复作用下，裂纹扩展，最终导致弹条断裂。试验证明了弹条微动磨损理论分析的正确性，为改进弹条设计，提高其疲劳寿命提供科学依据。
탄조시실현탄조II형구건공능적주요원건，전통적피로분석방법주요종탄조적응력、응변입수，저병불능반영진실정황，인위탄조재공작중여기타구건접촉면표면지간존재미소적상호이동，즉미동。응용비선성접촉이론，채용고륜마찰모형모의탄조여주위접촉원건지간적마찰접촉정황，계산출탄조각점적전절응력τ、상대위이δ급이자승적τ·δ적치；병채용리산렬봉모형래모의구건렬문적생성급확전。이론분석표명，약미동마손재탄조피로단렬과정중기주요작용，칙단구처응위우탄조중τ·δ치최대적점부건。구건피로시험표명，탄조단구처위우탄조미부여궤거당판접촉처，처우τ급τ·δ최대적점지간차경고근τ·δ치최대적점。탄조미부여궤거당판지간유우미동마손산생렬문，형성오염원，반복작용하，렬문확전，최종도치탄조단렬。시험증명료탄조미동마손이론분석적정학성，위개진탄조설계，제고기피로수명제공과학의거。
The function of type II fastener is mainly achieved by the elastic bar.The traditional methods for the study of fatigue dealing with stress or strain do not reflect the true situation because the contact surface between the elastic bar at work and other with other components leads to tiny mutual movement,namely fretting.The shear stress(τ),relative displacement(δ)and the product of them(τ·δ)of the elastic bar are calculated by application of the nonlinear contact theory and the Coulomb friction model.A discrete crack model is then used to simulate the fastener crack generation and propagation.It is shown through theoretical analysis that the fatigue fracture should be located in a section close to the maximum value of the τ·δif the fretting wear plays a major role.Fastener fatigue tests indicate that,a fracture is found at the tail of elastic bar and baffle contact,which is between points of theτvalue and the maximumτ·δvalue,while being a little closer to the latter one.The fret-ting wear between the tail elastic bar and baffle results in cracks,which are then propagated repeatedly and leads to the eventual fracture.The correctness of the fretting wear theory is proved by the experiment,which provides scientific basis for improving the fastener design and enhancing its wearability.