Finite-thickness interphases between different constituents in heterogeneous materials are often replaced by a zero-thickness interface model. Commonly accepted interface models intuitively assume that the interface layer is situated exactly in the middle of its associated interphase. Furthermore, it has been reported in the literature that this assumption is necessary to guarantee the balance of angular momentum on the interface. While the interface coincides with the mid-layer of a uniform interphase, we argue that this assumption fails to sufficiently capture the behavior of graded or inhomogeneous interphases. This contribution extends the formulation of the general interface model to account for arbitrary interface positions. The issue of angular momentum balance on general interfaces is critically revisited. It is proven that the interface position does not necessarily have to coincide with the mid-layer in order to satisfy the angular momentum balance. The analysis here leads to a unique definition of the controversially discussed interface configuration. The presented general interface model is essentially based upon the weighted average operator instead of the commonly accepted classical average operator. The framework is geometrically exact and suitable for finite deformations. The significance of the interface position is demonstrated via a series of examples where the interface position is identified based on a full resolution interphase.

异质材料中不同成分之间的有限厚度界面通常被零厚度界面取代模型。普遍接受的接口模型直观地假设接口层恰好位于其关联的相间中间。此外，据文献报道，该假设对于保证界面上角动量的平衡是必要的。虽然界面与均匀相间的中间层重合，但我们认为此假设无法充分反映渐变或不均匀相间的行为。该贡献扩展了通用接口模型的公式化，以说明任意接口位置。一般接口上的角动量平衡问题已被重新审视。已经证明，界面位置不一定必须与中间层一致才能满足角动量平衡。此处的分析得出了有争议的接口配置的唯一定义。提出的通用接口模型基本上基于加权平均算子代替了公认的经典平均算子。该框架的几何形状精确，适合于有限的变形。界面位置的重要性通过一系列示例进行了演示，其中基于全分辨率界面相识别界面位置。