COFS in-house technical team develops a wide range of equipment suitable for centrifuge and field work. A multi-skilled team with extensive experience in mechatronics, electrical, electronic and software engineering ensures that all aspects of the NGCF operations are supported.
DigiDAQ is a complete compact data acquisition system designed to meet the needs of today’s centrifuge testing. Versatility and simplicity of the unit allows the system to be used on many different applications, on centrifuges, in the laboratory or in the field. It comprises signal conditioning and A/D conversion in one rugged g-rated water-proof unit with the capability of real time data acquisition on up to 64 channels, and high speed simultaneous capture at up to 1 million samples per second. The software and hardware platform developed for DigiDAQ has been implemented in various formats. This has allowed the development of several instruments that utilise an embedded wireless DAQ system. The DigiDAQ Graphical User Interface provides data logging from sensors connected to a digiDAQ unit and also collects data from other sources such as PACS and the Centrifuge Control System.
The Package Actuator Control System has been developed specifically to meet the complex demands of motion control during centrifuge model testing. It provides the user with the flexibility of connecting most industry standard actuators, servo controlled devices, and analog feedback devices. The software provides the user with four PID Controller channels which can be set up individually in either displacement or force control, and synchronized using a built in waveform and sequence generator. Channels can also be linked using event limits providing a powerful tool for automating and customizing tests. Data from the PACS software is also transmitted to the Data acquisition software providing a comprehensive time-stamped record of all sensors and motion control data.
Soil Characterisation Tools
The NGCF designs and manufactures its own soil characterisation tools, including T-bar, cone, ball, piezocone and piezoball penetrometers. This provides researchers with greater flexibility when designing specific centrifuge model tests, and better control of the parameters being measured. Over the last few years, variations of these penetrometers were developed to answer specific modelling challenges. These includes notably the mini ball penetrometer, developed to measure the strength of clay overplayed by sand, and for which the sensing element features strain gauges embedded into an epoxy shaft.
The NCGF manufactures all the models used for centrifuge modelling, using a range of high precision equipment such as a centre lathe, DEM/CNC wire cutting machine and 3D printing. This enables specific features of full-scale geotechnical structures to be replicated in detail, including ‘keying flaps’ on suction embedded plate anchors, internal ring stiffeners on suction caissons or the thin flukes on dynamically installed anchors.