| Popis: |
This paper summarizes predesign considerations, the design, construction and commissioning activities in producing a novel testing facility at C-CORE. A large scale experimental apparatus was required to conduct impact testing between large ice samples and various impactor geometries. The equipment frame had to be self-reacting, mechanically rigid, fully instrumented to measure force and velocity, and capable of adaptation to different types of experimental setups. Design force testing capacities were set to 2 MN horizontally and 4 MN vertically. The moving horizontal test axis design velocity goal was set to 0.5 m/s. Actuation of the moving indenter system is with hydraulic cylinders having a piston diameter of 7". The rod diameter is 5". Hydraulic power for the test is supplied by two hydraulic accumulators, initially charged via a small, high pressure pump, and backed by gas bottles and a nitrogen skid. Various indenters can be attached to the test carriage indenter beam with adapter plates. Loads are transferred from indenter structures via high capacity bolted connections and precisely machined shear key features. The indenter beam is modular to facilitate changes and updates for future experimental test series, and fully instrumented with high capacity load cells. The reaction end of the instrumentation is mechanically isolated from the test carriage and its support track and roller system to eliminate friction forces in test measurements. The test carriage consists of two side plates joined by two beams, forming an open box structure into which the instrumentation and indenter beam assembly is situated. Height of the indenter beam relative to the test sample mounting area is infinitely adjustable via a set of 1" thick steel plates. Two bolt patterns are arranged in each of eight plates to allow any relative height difference to be set. The spacing of the bolt pattern on the instrumentation side is such that two settings are possible with each set of plates. If another height is required a new set of plates can be water-jetted with no further machining required. With the exception of the control system and hydraulic power skid, all design and FEA was carried out at C-CORE. Construction of the many components was carried out by one welding shop and six machine shops. When assembled, a process of tuning the hydraulics and control system commenced. After tuning had been completed the first test was conducted with success. This first test used an indenter that is 6" diameter and 63" (1600mm) long. The indentation depth was 1.5" (38.1 mm) and the test stroke was 80" (2032 mm). The load cells registered peak horizontal and vertical loads of 0.150 MN and 0.317 MN, respectively. |
