The experimental facilities of the Mechanics of MetaMaterials and Extreme Structures lab is housed primarily at Block V of the main building of IIT Delhi. We perform fundamental experiments to study mechanical problems ranging from the static and dynamic behavior of architected metamaterials to multi-physical modelling and prototyping of wind turbines and piles. A wide range of both custom-built and commercial instrumentation allows us to probe these complex problems across length and time scales. Experiments are designed with the goal of discovering new phenomena, measurement of fundamental processes in materials as well as validation of computational material models developed within the lab.
The MMMES Lab, IIT Delhi houses some state-of-the-art experimental facilities, as follows,
Electro Dynamic Vibration Test System
The Electro Dynamic Vibration Test System is primarily used to measure the time history responses of a structure subjected to harmonic loading. The test system consists primarily of an electrodynamic shaker and power amplifier cum signal generator. The power amplifier generates and amplifies the signal sufficiently to drive the electrodynamic shaker to the desired level, and also provides the necessary protections to the shaker as well as the power amplifier section.
2. Impedance Tube
The Impedance tube is designed to measure sound absorption coefficient and transmission loss as per test standards ASTM E1050 / ISO 10534-2. The measurement software is based on the Transfer Function Method. The Transfer Function method separates the incident and reflected energy from the measured transfer function, and then estimates the acoustic properties of the test sample. The sound transmission loss module is as per ASTM E2611. Alfa Acoustics offers a complete set of Impedance Tube system, which includes: the tubes, microphones; Data Acquisition hardware and measurement software.
3. Laser Doppler Vibrometer
The Laser Doppler Vibrometer(LDV) is used to measure non-contact vibration measurements of a surface. While experimenting, the laser from the particular instrument is directed at the surface of interest, i.e., the surface whose vibration amplitudes need to be measured. The instrument uses the principle of the Doppler effect(or Doppler shift) wherein the amplitudes of vibration are extracted from the Doppler shift of the reflected laser beam frequency due to the motion of the surface. It is primarily used in experiments wherein a physical transducer such as an accelerometer is difficult to attach, or where the targets whose vibrations are to be measured are difficult to access.
4. 3D Printers
The lab hosts several 3D printers of Creality Ender-3 V2 3D printers. The presence of 3D printers in the laboratory helps create model prototypes used in experiments.
5. Linear Variable Differential Transformer(LVDT)
The research laboratory hosts a set of LVDTs, which are position sensors that can sense and convert linear motion or vibrations into electrical signals or a variable electrical current in the circuit. LVDTs are primarily used in our laboratory to measure displacement amplitudes directly in experiments. The primary advantage of using LVDTs lies in the fact that other sensors available in our laboratory, such as accelerometers, measure acceleration time history, and the conversion of acceleration data into displacement data requires numerical integration, which in turn involves several errors, and hence LVDTs provide accurate displacement time history, compared to the one we obtain from accelerometer reading. It is also sensitive to small displacements and does not require the application of an amplifier to enlarge the signals. The LVDTs are of small size and are very lightweight, and hence can be placed as per the requirements of the experiment.
5. Workstations
Our lab currently hosts two workstations with high computational power. The systems has high speed Intel(R) Xenon(R) Gold 6226R CPU @ 2.90Ghz processors and 128 GB RAM.
6. Accelerometers
Our research group is equipped with cutting-edge accelerometer technology, catering to diverse research needs. The facility boasts state-of-the-art monoaxial accelerometers, specialized in capturing precise acceleration data along a single axis. These instruments are invaluable for studies requiring focused analysis of linear motion or specific directional forces. Additionally, our facility houses advanced triaxial accelerometers, elevating research capabilities to a three-dimensional level. These triaxial sensors provide a comprehensive understanding of motion dynamics by simultaneously measuring acceleration along three perpendicular axes—x, y, and z. This versatility makes them ideal for a wide range of applications, from biomechanics research to electronic stability control in various systems. Our commitment to providing researchers with access to both monoaxial and triaxial accelerometer technologies reflects our dedication to facilitating nuanced and impactful investigations across multiple disciplines.