Engineering Research Equipment Grant: Development of a Plane Strain Apparatus for Soft Rock and Concrete

本工作的目的是研制一种平面应变仪 对于“软”（无侧限抗压强度低于35 MPa）岩石 和混凝土，基于刚性框架设计。 独特的 该装置的特征在于， 形成了一个失败的平面。 通过将 上压板上的线性轴承，试样有自由， 形成由两个分离的刚体组成的破坏机制 由局部变形区造成的 应力是静态的 在整个载荷历史中，即使在大范围内， 流离失所。 通过声发射的位置映射了破坏过程 排放 讨论了摩擦约束问题， 提出了一种仪器化方案。 研究项目为 平面应变仪将被使用，涉及 验证分叉现象和确定 本构模型的材料参数。

The objective of this work is to develop a plane strain apparatus for "soft" (unconfined compressive strengths below 35 MPa) rock and concrete, based upon a stiff-frame design. The unique feature of the device is that no kinematical constraints are imposed on the formation of a failure plane. By placing the upper platen on a linear bearing, the specimen has the freedom to form a failure mechanism consisting of two rigid bodies separated by a localized zone of deformation. The stresses are statically determinate throughout the load history, even at large displacements. The failure process is mapped by the locations of acoustic emissions. The problem of frictional constraint is addressed and an instrumentation plan is suggested. The research projects for which the plane strain apparatus will be used, involve the verification of bifurcation phenomena and the determination of material parameters for constitutive models.