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

工程研究设备资助：软岩和混凝土平面应变仪的开发

• 批准号: 8906185
• 负责人: Joseph Labuz
• 金额: $ 7.19万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-06-15 至 1992-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8906185&HistoricalAwards=false
• 关键词: Engineering; Research; Equipment; Grant; Development

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.

这项工作的目的是开发一种基于刚性框架设计的用于“软”（无侧限抗压强度低于 35 MPa）岩石和混凝土的平面应变装置。 该装置的独特之处在于，对失效平面的形成没有施加运动学约束。 通过将上压板放置在线性轴承上，样本可以自由地形成由局部变形区域分隔开的两个刚体组成的失效机制。 即使在大位移下，应力在整个载荷历史过程中也是静态确定的。 故障过程通过声发射的位置来绘制。 解决了摩擦约束问题并提出了仪器计划。 使用平面应变仪的研究项目涉及分岔现象的验证和本构模型材料参数的确定。