Equipment

MARK TWO 3D printer for CFRP, GFRP, KFRP composite materials.

The MARK TWO 3D printer has the capability to deposit continuous fibers that can be used to reinforce the component made of a polymeric material. This technique allows the fibers to be arbitrarily oriented in each layer of the component. The printer has a printing volume capability of 320 x 132 x 154 mm.

Different polymeric materials can be used: nylon and onix (a polymer reinforced with chopped fibers)

Different fibers can be adopted to reinforce the component: carbon fiber, fiberglass, fiberglass for high temperature applications and Kevlar.

Brüel & Kjær LAN-XI module for portable noise and vibration measurements

Multichannel sound and vibration data acquisition hardware by Brüel & Kjær made of:

• 12-ch. input Module LAN-XI 25.6 kHz Type 3053. A stand-alone, single-module front end for small setups with 12 channels (frequency range 0-25.6 kHz).
• A rechargeable Li-Ion battery module that powers LAN-XI input modules and frames. The battery provides an autonomy of approximately 7 hours, which make the system good for flight tests of small aircraft setups.

The Brüel & Kjær LAN-XI module incorporates a wireless front-end for online data recording (Sonoscout). Furthermore, it is fully compatible  with PULSE LabShop and BK Connect PC-based software tools for data acquisition and elaboration.

Response of the structure due to the excitation are measured with accelerometers from DeltaTron and having a sensitivity of 10 mV/ms². The accelerometers are uni-axial.

Excitation is provided by using either a PCB Piezotronics hammer with medium-soft to hard head tips or a shaker. The hammer has a sensitivity of (± 15 %) 10 mV/lbf (2.19 mV/N); measurement range is ± 500 lbf pk (± 2224 N pk); and mass is 0.34 lb (0.16 kg).

LDS 14-kg shaker

The LDS® V400 series shakers are wide-frequency band electro-dynamic transducers capable of producing a sine force up to 196 N. They are also suitable as non-seismic pick-ups and are widely used in educational and research establishments to investigate the dynamic behaviour of structures and materials. The shakers efficient armature design enables them to deliver impressive peak forces and accelerations over a wide frequency range.

2-cameras DANTEC Digital Image Correlation system.

The DIC instrument is a Q-400 DIC system by Dantec Dynamics, whose optical features allow to measuring true full field, non-contact and three-dimensional shape, displacements and strains on components and structures made from almost any material. The Q-400 system can be used for determination of three-dimensional material properties in tensile, torsion, bending or combined tests.

This apparatus, essentially, is made of two 2-megapixel cameras for high-resolution and high-frequency image tracking, one led lamp, the supporting structure, the data acquisition unit, and the calibration tool.

Image processing, on the other hand, is performed with the licensed Instra4D V2.1 software tool.

The Q-400 system is shown in the figures during preliminary set-up in the laboratories of Politecnico di Torino. A few DIC acquisitions are also demonstrated.