Test apparatus for static simulation of earthquake response and verification of seismic design formulas

设计并组装了一个试验装置，用于模拟结构在比实际地震反应速度慢得多的加载速率下对任意地震地面运动的反应。该装置包含齿轮和螺纹来产生、放大和传递力到测试试样。动力由带制动器的传统电动机提供。电机的转速由变频器调节，变频器的信号来自一台传统的个人电脑。计算机还通过数字应变仪从位移和负载传感器中检索数据。在最大恢复力为1.0吨，最大位移为6 mm时，将10秒地震持续时间划分为200个时间间隔步长，对选定的地震地震动进行模拟地震响应试验所需的典型时间约为1小时。所需的时间相当于每一个时间步长18秒。试验装置的总体性能令人满意。螺纹确保位移控制载荷。在确定位移时，机械载荷传递路径中的一些松弛性需要修正。地震模拟载荷试验正在进行中，并将继续进行。

A test apparatus was designed and assembled to simulate response of structures to an arbitrary seismic ground motion at loading rates much slower than actual seismic response velocity.The apparatus incorporates gears and threads to generate, magnify, and transmit force to a test specimen. Driving force is given by a conventional electric motor with brake.Rotational velocity of the motor is adiusted by a frequency inverter to which signals are sent from a conventional personal computer. The computer also retrieve data from displacement and load sensors through a digital strain meter.A typical time required to conduct a simulated seizmic response test for a selected earthquake ground motion was about one hour when the maximum restoration force was 1.0 ton, the maximum displacement was 6 mm, and the 10 seconds duration of earthquake was devided into 200 time interval steps. That required time corresponds to 18 seconds per one time step.The overall performance of the test apparatus was satisfactory. The threads ensures displacement control loading. Some slackness in the mechanical load tranmission paths requires corrections in determining displacements. Seismic simulation load tests are underway and will be continmed.