Fatigue of titanium alloys in a supersonic-cruise airplane environment

The test programs conducted by several aerospace companies and NASA, summarized in this paper, studied several titanium materials previously identified as having high potential for application to supersonic cruise airplane structures. These studies demonstrate that the temperature (560 K) by itself produced no significant degradation of the materials. However, the fatigue resistance of titanium-alloy structures, in which thermal and loading effects are combined, has been studied insufficiently. The predominant topic for future study of fatigue problems in Mach 3 structures should be the influences of thermal stress particularly, the effects of thermal stress on failure location

Crack growth in Ti-8Al-1Mo-1V with real-time and accelerated flight by flight loading

Crack growth in Ti-8Al-lMo-lV was measured and calculated for real time and accelerated simulations of supersonic airplane loading and heating. Crack-growth rates calculated on the assumption that an entire flight could be represented by a single cycle predicted the experimental rates poorly. Calculated crack growth rates were slower than the experimental rates for all tests with flight-by-flight loading. For room temperature accelerated tests, the calculated rates agreed well with the experimental rates; but the calculations became progressively less accurate for progressively more complex test conditions (tests that included elevated temperature)

Fatigue testing device

Anti-buckling assembly prevents buckling of sheet metal fatigue specimen when axial compressive load is applied. It provides for cyclic heating and cooling of specimen during testing. Assembly permits tests at two locations on specimen. Device has ports for visual, optical, or photographic monitoring of fatigue crack propagation in test specimen

Heating and cooling system

A heating and cooling apparatus capable of cyclic heating and cooling of a test specimen undergoing fatigue testing is discussed. Cryogenic fluid is passed through a block clamped to the speciment to cool the block and the specimen. Heating cartridges penetrate the block to heat the block and the specimen to very hot temperaures. Control apparatus is provided to alternatively activate the cooling and heating modes to effect cyclic heating and cooling between very hot and very cold temperatures. The block is constructed of minimal mass to facilitate the rapid temperature changes

Anti-buckling fatigue test assembly

An antibuckling fatigue test assembly is described for holding a metal specimen which is subjected to compression and to rapid cyclical heating and cooling while permitting visual observation. In an illustrative embodiment of this invention, the anti-buckling fatigue test apparatus includes first and second guide members between which the metal specimen is disposed and held, a heating assembly comprising a suitable heating source such as a quartz lamp and a reflecting assembly directing the heat onto the specimen, and a cooling assembly for directing a suitable cooling fluid such as air onto the specimen. The guide members each have a passage to permit the heat to be directed onto the specimen. An opening is provided in the reflecting assembly to permit visual inspection of that region of the specimen adjacent to the opening onto which the heat is directed

Pockets of Positivity: School leaders’ Strategies for Developing School Inclusion for Students with Refugee and Asylum-seeking Backgrounds

Currently, millions of children and families with refugee and asylum-seeker experiences find themselves living in new countries, with different languages, dissimilar cultures, diverse expectations, and different forms of schooling. For school leaders, the challenge of integrating these students and their families, some of whom may have endured and be dealing with trauma and loss, can be challenging. This paper presents findings from a study involving twenty-two school leaders in five English-speaking Western countries (Australia, England, New Zealand, Northern Ireland and the United States), who have created places of wellbeing and belonging for these families. Five major findings from the research are discussed and suggestions for school leaders are offered. Of note, school leaders working with children and families with refugee and asylum-seeker experiences are encouraged to identify and implement high-quality ongoing professional development for staff. These leaders must learn to work within and to modify existing school policies that often have deleterious effects on this group of students and become adept at navigating the web of external resources and organisations that can offer support beyond what schools can provide. This research also offers suggestions for educator/teacher preparation programs as it is evident that working with and supporting this population is not a competency covered in most training programs

Fatigue failure load indicator

An indicator for recording the load at which a fatigue specimen breaks during the last cycle of a fatigue test is described. A load cell is attached to the specimen which is alternately subjected to tension and compression loads. The output of the load cell which is proportional to the load on the specimen is applied to the input of a peak detector. Each time the specimen is subjected to a compression load, means are provided for applying a positive voltage to the rest of the peak detector to reset it. During the last cycle of the tension load the peak detector measures the maximum load on the specimen. Means are provided for disconnecting the load cell from the peak detector when there is a failure in the specimen

Attitude Changes Resulting from a Course in Middle East History

This study explored the change in high school students\u27 cultural acceptance of Islamic peoples after a semester long course in Middle East History. Ten senior high school students in a small Christian high school were tested in knowledge, visual perception, and cultural attitudes before and after the semester course. Final data collection suggests that the population size for this study needed to be larger and more diverse. The results were not significant enough to indicate attitudes were changed over the course of the semester. There was not a positive correlation found between knowledge gained by the students and the resulting changes in attitudes. Implications resulting from this test suggest that there is some type of relationship between the increasing knowledge of students and their attitudes towards people of different cultures. Based on the final correlational results, further study is suggested to examine possible negative correlation between knowledge gained and cultural acceptance