0000000000717306
AUTHOR
L. Mistretta
Low cost electrical current sensors with automatic measurement range
We present a simple and low cost Smart Current Sensor with wide automatic measurement range. The logic core system of the sensor is the Atmel AT32UC3C2256C AVR 32-bit microcontroller, the wireless core is a Microchip MRF24J40MA IEEE 802.15.4 RF transceiver[3]. The MCU features 11 ADC multiplexed channels, with 12-bit resolution and sample rate up to 2Msps, two of which can be sampled in parallel. The sensing board consists of two hall-effect based current sensors, assembled on different PCBs in order to perform with different sensitivities. Custom primary conductor design allowed us to sense the current flowing in the conductor with two different sensitivities: the sensor mounted inside the…
Crack growth analysis at adhesive–adherent interface in bonded joints under mixed mode I/II
The propagation of an interface crack subjected to mixed mode I/II was investigated for two 2024-T351 aluminum thin layers joined by means of DP760 epoxy adhesive produced by 3M©. On the basis of beam theory, an analytical expression for computing the energy release rate is presented for the mixed-mode end loaded split (MMELS) test. The analytical strain energy release rate was compared by finite element (FE) analysis using the virtual crack closure technique (VCCT). Several fatigue crack growth tests were carried out in a plane bending machine to compare the experimental energy release rates to those of the analytical and FE solutions. Experimental results showed the relationship between t…