Weibull Failure Distribution Research Articles

Catastrophic Failures in Semiconductor Devices Exposed to Pulsed Radiation

Semiconductor devices were exposed to high intensity 1.6 MeV electron pulses. Glass diode packages and integrated circuit chips were broken. However, the failure occurring at the lowest radiation doses is lead-chip separation at the point where the lead is bonded to the chip. Statistical experiments show that the damage is caused by energy absorption in the device, and, assuming a Weibull failure distribution, give the probability of failure as P = 1 - exp[-0.00708 (㩣.15)], where P is the probability that a given gold-silicon bond will fail when exposed to dose Φ, and Φ is the incident pulsed radiation dose in gramcalories/cm2. A technique based on absorbed doses and differential temperature rises is suggested to correlate these results with other environments. 90% confidence level failure rates and survival probabilities for many lead systems are also given.

The coefficient of drag of circular plates in the oscillatory flow of a fluid: Okeanologiya, 1961. 1 (5) : 911–914

Measuring the strengths of asteroidal materials is important for developing mitigation strategies for potential Earth impactors and for understanding properties of in situ materials on asteroids during human and robotic exploration. Studies of asteroid disruption and fragmentation have typically used the strengths determined from terrestrial analog materials, although questions have been raised regarding the suitability of these materials. The few published measurements of meteorite strength are typically significantly greater than those estimated from the stratospheric breakup of meter-sized meteoroids. Given the paucity of relevant strength data, the scale-varying strength properties of meteoritic and asteroidal materials are poorly constrained. Based on our uniaxial failure studies of centimeter-sized cubes of a carbonaceous and ordinary chondrite, we develop the first Weibull failure distribution analysis of meteorites. This Weibull distribution projected to meter scales, overlaps the strengths determined from asteroidal airbursts and can be used to predict properties of to the 100 m scale. In addition, our analysis shows that meter-scale boulders on asteroids are significantly weaker than small pieces of meteorites, while large meteorites surviving on Earth are selected by attrition. Further, the common use of terrestrial analog materials to predict scale-dependent strength properties significantly overestimates the strength of meter-sized asteroidal materials and therefore is unlikely well suited for the modeling of asteroid disruption and fragmentation. Given the strength scale-dependence determined for carbonaceous and ordinary chondrite meteorites, our results suggest that boulders of similar composition on asteroids will have compressive strengths significantly less than typical terrestrial rocks.