Abstract The improvement of Johnson's model ( Johnson (1970) , (1985)) takes into account the additional pressure and shear stresses jump at the boundary with the hydrostatic core where it is formed from the material of the elastic-plastic zone. This causes additional volumetric deformations and additional pressure in the core that increases the magnitude of the constant in the Tabor ratio. The effects of the proposed improvement of the Johnson model: additional volumetric deformations and pressure in the core, changes in the Tabor constant and related values of yield strength as well as characteristic size of the elastic-plastic region, were determined on a wide class of materials with different elastic-plastic properties. An analysis of the concept of characteristic (representative) strain is given for these materials.

中文翻译：

---

弹塑性材料力学性能试验测定压痕的改进型芯模型及其应用

摘要 Johnson 模型(Johnson (1970), (1985)) 的改进考虑了在流体静力核心边界处的附加压力和剪切应力跳跃，该边界由弹塑性区的材料形成。这会导致核心中的额外体积变形和额外压力，从而增加 Tabor 比率常数的大小。约翰逊模型的拟议改进的影响：核心中的附加体积变形和压力、Tabor 常数的变化和屈服强度的相关值以及弹塑性区域的特征尺寸，是在广泛的类别上确定的具有不同弹塑性特性的材料。对这些材料的特征（代表性）应变的概念进行了分析。