Acquisition of 500 kN (110 kip) Servo-Hydraulic Test Machine

摘要：主要研究仪器拨款用于购买一台500千牛（11万磅）容量的伺服液压拉力/压缩试验机，该试验机具有应用循环载荷的能力。测试机器将有一个十字头安装的执行器，以最大限度地灵活地测试样品的类型。测压元件和底座之间的开放空间为3米，允许测试长样品。除了负载和行程输入外，还有两个通用调节器和六个预置（DC）输入通道的额外通道；所有通道都可以用作反馈控制，甚至是信号的组合。试验机的主要用途是用于高级项目和硕士论文的研究。pi在以下领域有特定的正在进行的或拟议的研究，其中工作的智力价值将受益于新测试机器的独特功能：(1)破坏局部化对混凝土压应力-应变特性的影响；(2)钢筋混凝土构件裂缝萌生与扩展的量化；(3)铺装材料弹性模量的测定；(4)机械节点疲劳与强度试验；(5)缠绕复合管材支板压缩试验。获得的测试机器填补了圣路易斯奥比斯波加州理工大学整个工程学院测试能力的空白。PI和联合PI代表工程学院的三个不同部门。土木与环境工程已经有了大载荷和小载荷的试验机；然而，没有一台试验机能够施加循环载荷或使用反馈信号控制试样的脆性断裂。航空航天系和机械工程系都有具有循环拉/压缩能力和闭环反馈控制的伺服液压试验机；然而，每个部门的最大容量机器是100千牛（22,000磅）。与目前的任何测试设备相比，拟议的测试机器在加载面之间也将有更大的清晰空间。学生和当地社区都将受益于获得测试机器的广泛影响。加州理工学院是美国最大的非博士学位授予工程学院之一，本科招生人数超过4500人，硕士课程也在不断增加。加州理工学院要求每位学生都必须完成一个高级项目，并坚持“动手”的理念，新仪器将成为帮助众多学生了解最先进的测试设备的能力并帮助他们更好地理解材料力学行为的宝贵资产。此外，在加州理工学院进行的许多研究都是实践性的，服务于该州的工业和公共机构的需求。吸引资金也有助于当地社区，因为当地社区与主要大都市地区隔绝，除了大学之外几乎没有其他产业。测试机器将位于新的铺装材料和先进CE材料实验室。该实验室将在项目负责人和其中一名合作项目负责人的联合监督下运作。这个实验室位于加州理工学院校园的13号楼。13号楼是土木、机械和航空航天工程系的主要办公地点；他们的部门办公室，实验室和教师大多包含在这座建筑内，方便访问设备。PI在其他机构拥有丰富的闭环测试研究经验；他开发了独特的闭环测试技术，可以实现其他方法无法实现的测量。PI将是主要操作员，并将为使用设备的人员提供培训，以便充分利用机器的全部功能。土木环境工程部将负责对试验机进行定期维护和校准。

ABSTRACTThis Major Research Instrumentation grant is for the acquisition of a 500 kN (110,000 lbs.) capacity servo-hydraulic tension/compression test machine with the ability to apply cyclic loading. The test machine will have a cross-head mounted actuator for maximum flexibility in the types of samples which can be tested. The open space between the load cell and the base is three meters, allowing for testing of long specimens. In addition to inputs for the load and stroke, there are additional channels with two universal conditioners and six channels of preconditioned (DC) input; all channels can be used as feedback control or even a combination of signals. The primary uses for the test machine will be for senior projects and research for Master's theses. The PIs have specific ongoing or proposed research in the following areas in which the intellectual merit of the work would benefit by the unique capabilities of the new test machine: (1) effect of failure localization on compressive stress-strain behavior of concrete, (2) quantification of the initiation and growth of cracks in reinforced concrete members (3) determination of the resilient modulus of paving materials, (4) fatigue and strength testing of mechanical joints, and (5) compression tests of filament wound composite tube struts. The test machine being acquired fills a gap in the testing ability for the entire College of Engineering at the California Polytechnic State University at San Luis Obispo. The PI and co-PIs represent three different Departments within the College of Engineering. Civil and Environmental Engineering already has test machines with greater and lesser load capacity; however, none of the test machines have the ability to apply cyclic loads or control brittle fracture of specimens using feedback signals. Aerospace and Mechanical Engineering Departments both have servo-hydraulic test machines with cyclic tension/compression abilities and closed-loop feedback control; however, the largest capacity machine in each department is 100 kN (22,000 lbs.). The proposed test machine will also have greater clear space between loading surfaces than any of the current testing facilities.The students and the local community will both be beneficiaries of the broader impact of acquiring the test machine. Cal Poly has one of the largest non-PhD granting engineering colleges in the country with undergraduate enrollments exceeding 4500 and a growing master's program. Coupling Cal Poly's requirement that every student must complete a senior project and its "hands-on" philosophy, the new instrument will be a valuable asset in helping numerous students understand what state-of-the-art test equipment is capable of and helping them better understand the mechanical behavior of materials. Furthermore, much of the research conducted at Cal Poly is of a practical nature, serving the needs of industry and public agencies within the state. Attracting funding also helps the local community which is isolated from major metropolitan areas and has little industry other than the University.The test machine will be located in the new Paving Materials and Advanced CE Materials Lab. This laboratory will be operated under the joint supervision of the PI and one of the co-PIs. This laboratory is housed in Building 13 on the Cal Poly campus. Building 13 is the primary location for the Civil, Mechanical, and Aerospace Engineering Departments; their Department offices, laboratories, and faculty are mostly contained within this building providing easy access to the equipment. The PI has extensive research experience with closed-loop testing at other institutions; he has developed unique closed-loop test techniques which allow for measurements which would not otherwise be obtainable. The PI will be the primary operator and will provide training to those using the equipment so the full capabilities of the machine will be utilized. The Civil and Environmental Engineering Department will the responsible party for regular maintenance and calibration of the test machine.