Results of the Round Robin on opening-load measurement conducted by ASTM Task Group E24.04.04 on Crack Closure Measurement and Analysis

An experimental Round Robin on the measurement of the opening load in fatigue crack growth tests was conducted on Crack Closure Measurement and Analysis. The Round Robin evaluated the current level of consistency of opening load measurements among laboratories and to identify causes for observed inconsistency. Eleven laboratories participated in the testing of compact and middle-crack specimens. Opening-load measurements were made for crack growth at two stress-intensity factor levels, three crack lengths, and following an overload. All opening-load measurements were based on the analysis of specimen compliance data. When all of the results reported (from all participants, all measurement methods, and all data analysis methods) for a given test condition were pooled, the range of opening loads was very large--typically spanning the lower half of the fatigue loading cycle. Part of the large scatter in the reported opening-load results was ascribed to consistent differences in results produced by the various methods used to measure specimen compliance and to evaluate the opening load from the compliance data. Another significant portion of the scatter was ascribed to lab-to-lab differences in producing the compliance data when using nominally the same method of measurement

Evaluating Air Force Civil Engineer\u27s Current Automated Information Systems

Almost every organization has some form of information system where data is captured and stored for later use. The Air Force civil engineering organization is no exception and is in the process of transitioning from the Interim Work Information Management System (WIMS) to the Automated Civil Engineer System (ACES). This research focused on users perceptions of both database and data importance to determine if significant differences existed between various user sub-groups. The research also attempted to identify the most frequently reported problems regarding system usage. The methods of analysis of variance and content analysis were used to answer the research questions using survey responses from a sample size of 814. The results indicate that civil engineers slightly agree that their database and the data it collects are important. However, significant differences in perception levels were found between men and women, between some major commands (MAJCOMS), between users of different systems, and between personnel of different rank. Content analysis of comments in response to open-ended questions found that users are generally satisfied with their current system. However, areas of concern included slow system speed, lack of a user-friendly report writing feature, and poor reliability

Calypso: Effecting Conflict Transformation Through the Indigenous Calypso Art-Form

The calypso, which forms an integral part of the carnival celebrations of the Republic of Trinidad and Tobago, is a syncretic popular art-form that has its origin in Africa. The art-form, having been influenced and adapted by the experiences of enslaved Africans in the Diaspora, has been fused in the vortex of plantation society. Today, the music of carnival has evolved considerably, with the calypso becoming one of the cornerstones of the carnival celebration. This paper looks at aspects of the subset of political calypsos that offer commentary on the socio-political and/or economic issues in the Republic of Trinidad and Tobago (Trinbago). It recognizes these calypsos as bedded in the popular practice of ritual resistance. In doing so this paper fuses the very diverse fields of ritual communication and Conflict Transformation with Trinbago history and culture. Hence, this text is not steeped in the ideological paradigm of a single academic discipline. The very nature of this work requires that it encompasses the dynamic interplay between popular art, music, language, calypso, and an understanding of the approaches and methods of Conflict Transformation, establishing a symmetrical balance between all of these fields. This article recognises the pre-existing forma/ and informal modes of dispute resolution. In extending on that duality, it adds a third non-formal cultural model of community conflict management which embodies the process of Conflict Transformation as described by Bush and Folger ( 1994), as this is applicable to Trinidad and Tobago\u27s local, temporal context. By adding this new set of intellectual tools, this paper enables the recognition of the language of the political calypso as Symbolic Action (Burke, 1966) in a process of Conflict Transformation

An Experimental Study of Fatigue Crack Growth in Aluminum Sheet Subjected to Combined Bending and Membrane Stresses

An experimental study was conducted to determine the effects of combined bending and membrane cyclic stresses on the fatigue crack growth behavior of aluminum sheet material. The materials used in the tests were 0.040-in.- thick 2024-T3 alclad and 0.090-in.-thick 2024-T3 bare sheet. In the tests, the membrane stresses were applied as a constant amplitude loading at a stress ratio (minimum to maximum stress) of 0.02, and the bending stresses were applied as a constant amplitude deflection in phase with the membrane stresses. Tests were conducted at ratios of bending to membrane stresses (B/M) of 0, 0.75, and 1.50. The general trends of the results were for larger effects of bending for the higher B/M ratios, the lower membrane stresses, and the thicker material. The addition of cyclic bending stresses to a test with cyclic membrane stresses had only a small effect on the growth rates of through-thickness cracks in the thin material, but had a significant effect on the crack growth rates of through-thickness cracks in the thick material. Adding bending stresses to a test had the most effect on the initiation and early growth of cracks and had less effect on the growth of long through-thickness cracks