bluuebunny/crossref_metadata_2025 huggingface dataset:
The Energy Issue
Authors: Strand Paul J.
Published: March 2007

This study finds that, although energy policy preferences are related to political party identification, they are often more strongly related to perceived seriousness of the energy situation, to education, and to age. Those who perceive the situation to be serious, and the young, are more likely than others to favor conservation and abandonment of existing energy supplies in favor of nonconventional supplies. Also, the partisan dimension of the energy issue is found to increase as consideration of the issue becomes more specific.
College Classroom Environment
Authors: Wollin Dorothy D. , Montagne Mary
Published: March 2007

Effects of classroom physical environment were studied by adding bright wall paint, posters, kites, rugs, softer lighting, cushions, and plants to a college classroom while an identical control classroom was left barren and sterile. Two Introductory Psychology classes (students and instructors) were exposed to both experimental and control classrooms for one-half quarter (five weeks). Dependent variables were: amount of learning as measured by scores on academic tests taken in each room, student evaluation of teacher performance, student-teacher interaction, student attitude toward classroom environments, and amount of vandalism in each room. It was found that students had significantly higher percentage correct on the tests (F = 5.11, df = 1.90, p <.0005), and teachers were rated significantly more positively in the experimental room. Differences in student-teacher interaction were not significantly different between the class-rooms. Student attitudes toward the experimental room were significantly more positive than toward the control room, and no vandalism occurred in either room.
Programming, Space Planning, and Office Design
Authors: Davis Gerald , Szigeti Francoise
Published: March 2007

The processes of programming, space planning, and design of office environ ments can support or constrain access to and consideration and utilization of user-oriented information. This article summarizes the process approaches commonly used in Canada and the United States to plan office environments and generate user-oriented design requirements. Constraints and opportu nities inherent in each approach are discussed. Future trends and research directions are suggested.
Status Demarcation in the Office
Authors: Konar Ellen , Sundstrom Eric , Brady Christine , Mandel David , Rice Robert W.
Published: March 2007

A survey of 529 office workers from three government and three private sector organizations explored the environmental characteristics that demarcate status in the office, the extent to which these characteristics are related to a sense of status support, and the association of status support with workspace and job satisfaction. Four types of environmental characteristics (the nature of workspace furnishings, amount of space, capacity for personalization, and the ability to control access by others) discriminated between supervisory (high-status) and nonsupervisory (lowstatus) respondents. Furthermore, each of the four sets of physical environment properties were related to perceptions of appropriate status support, which was in turn predictive of job satisfaction and satisfaction with workspace. Private versus public sector differences and supervisory versus nonsupervisory differences were explored The implications for space planning and evaluation are considered.
Visual Preferences in Enclosed Urban Spaces
Authors: Im Seung-Bin
Published: March 2007

Few design approaches have utilized scientific methods in dealing with aesthetic and visual factors. In an attempt to explore a scientific approach to environmental design, the relationship between visual preference and ratio variables in enclosed spaces on the Virginia Tech campus was investigated. Visual preference of enclosed spaces was measured by the Scenic Beauty Estimation (SBE) method. The SBE method was found to be reliable and valid in urban enclosed spaces. This study suggests that visual quality of an enclosed urban place can be predicted from the linear combination of three ratio variables-ground slope, height ratio, and vegetation coverage. The prediction model can be used as an heuristic or analytic tool for design practice.
Children's Acquisition of a Route via Different Media
Authors: Cornell Edward H. , Hay Deborah H.
Published: March 2007

Route learning by kindergarten and grade 2 children was assessed via a slide presentation, videotape, or walking the route with a guide. The children viewed the route only once, and were then asked to retrace it in the same medium from start to finish or in the reverse. They were shown a panoramic view at seven choice points along the route, and when retracing were asked to point to the correct path at these locations. Older children were less likely to err than younger children, reversing the route was more difficult than repeating it in the forward direction. There was very little difference in overall performance in slide and videotape media, but significantly fewer errors occurred while walking, especially when children were asked to indicate their way back to the start. Methodologically, these findings suggest caution should be exercised in generalizing from studies of children's spatial performance using bounded planar materials. Theoretically, these findings support accounts of route learning that ascribe a fundamental role to self-produced exploration and its concurrent spatio-temporal feedback (e.g., Gibson, 1966,1979).
Promoting Wheelchair Accessibility of Private Business Settings
Authors: Nelson Christopher F. , Jones Michael L. , Salkind Neil J.
Published: March 2007

This article documents barriers to access by wheelchair in a sample of privately owned, public use settings in a large midwestern city and describes efforts to prompt voluntary removal of barriers in these settings. Approximately 2,000 public use settings (e.g., hotels, restaurants, theaters) were surveyed to identify barriers to access by persons with disabilities. A sample of 420 at least partially accessible settings was selected to evaluate the effects of different intervention strategies in promoting barrier removal. Seven different intervention packages designed to encourage managers to call or write for free technical assistance in making their settings more accessible were evaluated. The intervention packages did not differ significantly in their effectiveness in prompting managers to request assistance. Phone calls to managers who did not receive intervention packages suggested that calls alone were as effective as the intervention packages in prompting managers to request assistance.
Distance and Direction Judgment in a Large-Scale Natural Environment
Authors: Okabe Atsuyuki , Aoki Ken , Hamamoto Wataru
Published: March 2007

This experiment was designed to demonstrate the effect of uphill and downhill walking on children's and adults' distance judgment and the effect of a winding trail on their direction judgment in a large-scale natural environment. First, it was shown that a traversed distance was overestimated not only in uphill walking but also in downhill walking. This overestimation was observed for both children and adults. Second, when a trail was winding and there was no landmark on the way, direction judgment was systematically biased toward the direction of the vanishing point of the trail viewed from the judging point. When there was a landmark on the way, this bias disappeared for adults but remained for children.
State-Sanctioned Self-Help and Self-Help Homebuilders in South Africa
Authors: Hart Tim , Hardie Graeme J.
Published: March 2007

Formal, state-sanctioned self-help housing for blacks in whitedesignated areas of South Africa is discussed. Based on two case studies, the actual and potential impacts of this form of self-help housing on the participants are examined. It is shown that national settlement policies and local interventions have to some degree constrained the range of user opportunities potentially opened up through the self-help process, and it is argued that the case studies presage the residential future of increasing numbers of South African black people.
"Christmas Street" as an Example of Transactionally Oriented Research
Authors: Altman Irwin , Werner Carol M. , Oxley Diana , Haggard Lois M.
Published: March 2007

Our study of "Christmas Street" (Oxley et al., 1986) was an illustration of the kind of research that might be undertaken within a transactional worldview. In the present article, we review some central philosophical principles of that worldview, how they differ from assumptions and principles of other worldviews, and how these principles influenced a variety of pragmatic decisions in our research. Some principles of this worldview are that phenomena should be studied holistically, should be expected to change with time and circumstances, and should be examined for their inherent patterns rather than for their "causeeffect" relationships. We conclude that our study of Christmas Street is a useful albeit imperfect application of the transactional worldview, and hope that it will stimulate further thought, discussion, and research from that perspective.
Effect of Menu Sign Position on Customer Ordering Times and Number of Food-Ordering Errors
Authors: Foster R. Spencer , Aamodt Michael G. , Bodenmiller James A. , Rodgers Jeffrey G. , Kovach Robert C. , Bryan Devon A.
Published: March 2007

Data were collected to determine if an additional menu sign, visible to restaurant customers as they waited in line to order food, would reduce both the amount of time taken to order food as well as the number of food-ordering errors. An A-B-A-B design was utilized in which ordering times and errors were recorded before the addition of a second menu sign, after the addition of the second sign, after the removal of the second sign, and after the reinstallation of the second menu sign. Results indicated that the additional menu sign led to a significant decrease in both ordering times and ordering errors. Without the second sign, customers took an average of 23.82 seconds to place an order and made an average of .26 errors. In the two sign intervention conditions, customers took an average of 6.48 seconds to order and made an average of .08 errors. The sign manipulation resulted in effect sizes of 1.18 for ordering times and .99 for ordering errors.
A Post-Jury Evaluation
Authors: Nasar Jack L. , Kang Junmo
Published: March 2007

Given the increasing use of architectural competitions to select an architect for public projects, this paper argues that Preand Post-Jury Evaluations (PJEs) are needed to monitor and improve competition results. For demonstration purposes, we conducted a Post-Jury Evaluation of the Ohio State University Competition for a Center for the Visual Arts. Using the criteria stated by the jury for their selection of the winner, we assessed public responses to the entries. The public ranked the winning entry as third or fourth out of five. The results confirm potential problems in the reliance on architectural experts to judge public reactions, and they demonstrate the need for further study of the jury process.
Physician Interest in Hospital-Provided Housing
Authors: Winkel Gary H. , Olsen Richard V.
Published: March 2007

Many urban hospitals face a staffing crisis as a consequence of a shrinking and more costly housing market. Hospital administrators are committing health resources to purchase or build housing for their staffs. Questionnaire data were gathered from 240 interns, residents, and fellows across a wide range of income levels and current housing costs to determine their interest in such housing and to assess their status in the current housing market. A simultaneous equation model was developed that included current housing conditions, housing problems, and satisfaction levels, as well as selected demographic variables. Results indicated that physicians with children and those with insufficient bedrooms were not interested in such housing. Lower-income single and married physicians without children were most interested.
Young Children's Preferences for School-Related Physical-Environmental Setting Characteristics
Authors: Cohen Stewart , Trostle Susan L.
Published: March 2007

Environmental preferences for size, shape, color, complexity, texture, and lighting within a school-related setting were examined among kindergarten and firstgrade school children. Using a guided "story-walk" as a prop, each characteristic was presented to the child in simplified pictorial contexts incorporating the school and its immediate surroundings. It was found that children discriminate, in selected fashion, in their preferential responses to physical-environmental characteristics of the environment. Findings of principal interest suggest that boys and girls respond differently to environmental features such as color, shape, light, and complexity, with girls demonstrating stronger preference for more diverse and dramatic environmental stimuli than do boys. The significance of this finding for evaluating spatial-cognitive knowledge among boys and girls is discussed.
Shame and Embarrassment as Deterrents to Noncompliance with the Law
Authors: Grasmick Harold G. , Bursik Robert J. , Kinsey Karyl A.
Published: March 2007

The present research draws from theories in criminology which suggest that threats of shame, a self-imposed punishment, and threats of embarrassment, a socially imposed punishment, function much like threats of state-imposed legal sanctions to reduce the expected utility of illegal behavior and, thus, to increase the likelihood of compliance with the law. Antilittering campaigns that appeal to citizens' conscience or sense of community pride are attempts to increase the threats of shame and embarrassment for littering. The antilittering campaign in Oklahoma is such an appeal. A sample of residents of Oklahoma City was interviewed in 1982, five years prior to the initiation of that campaign. Another sample was interviewed in 1989, two years after the campaign began. In 1982, 39% of the respondents indicated they probably would litter in the future, compared to 31% in 1989. In 1982, only 37% strongly agreed that they would feel guilty if they littered, compared to 67% in 1989. Likewise, in 1982, only 8% believed they definitely would lose the respect of others if they littered, compared to 21% in 1989.
Impact of Window Size and Sunlight Penetration on Office Workers' Mood and Satisfaction
Authors: Boubekri Mohamed , Hull Robert B. , Boyer Lester L.
Published: March 2007

Sunlighting or direct-gain passive solar strategies let sunlight penetrate the living space. In environments where the well-being of the building occupant is a salient concern to the designer, this intrusion of sunlight ought to be controlled so that it does not impede the performance of the occupant. This study investigates the impact of window size and different amounts of sunlight penetration on occupant emotional response and degree of satisfaction. Unlike previous sunlight requirement studies, sunlight penetration is measured not in terms of duration, but rather in terms of size of sunlit areas, and therefore as a visual stimulus. The study was performed in an office room of a typical size. It was found that window size did not significantly affect the occupant emotional state or the degree of satisfaction. Sunlight penetration significantly affected the feeling of relaxation when the observer was sitting sideways to the window and the relationship had an inverted U-shape. The study stresses the validity of this novel way of assessing sunlight penetration in terms of size of the sun patches inside the room and its importance as a significant environmental attribute and design parameter that ought to be accounted for during the design of windows in sunlighting or direct-gain passive solar strategies.
Environment and Economy
Authors: Gale Robert J. P.
Published: March 2007

Public interest in environmental policy formulation is analyzed from a development policy perspective. The objective is to assess the extent to which environmental issues are considered integral to decisions on the economy. Three policy models are considered: neo-classical economic development, socioeconomic development, and ecologically sustainable development. The study is based on data gathered from a content analysis of written testimony to a national public inquiry on development prospects (n = 1,119). Of this testimony, neo-classical and socioeconomic development models are explicitly supported by 26% and 63% of intervenors, respectively. Only 6% of the testimony supports the ecologically sustainable development model. The findings indicate that environmental issues are rarely considered integral to decisions on the economy and that support for genuine integration lies outside the institutional arrangements and decision-making centers of economic and social development.
Role of Control and Social Support in Explaining the Stress of Hassles and Crowding
Authors: Lepore Stephen J. , Evans Gary W. , Schneider Margaret L.
Published: March 2007

In a previous study, social hassles in the home, such as arguments and lack of privacy, were associated with greater psychological distress only in people living in crowded homes. Hassles were not related to distress in people in uncrowded homes. The current study undertakes a secondary analysis of these data to understand why household crowding potentiates the negative effects of social hassles on psychological well-being. The aim is to evaluate how two psychosocial variables—perceived control over the residential environment and social support from housemates—might explain the interactive effects of hassles and crowding on psychological distress. The results suggest that decreased perceived control among those who experience both crowding and hassles in the home explains why this subgroup has greater psychological distress. The authors argue that hassles in crowded homes lead to lower perceived control because household crowding constrains one's ability to avoid or escape from the hassles. Perceived social support from roommates does not account for the interactive effects of hassles and crowding.
Integrating Knowledge of Vertically Aligned Large-Scale Spaces
Authors: Montello Daniel R. , Pick Herbert L.
Published: March 2007

The acquisition and integration of configurational knowledge of spatial layout was studied in a large building complex containing several levels. Twenty-four college students learned two separate routes by walking around the complex; the two were located one above the other, although this was not visibly apparent. Subjects were then given a description that allowed them to integrate their knowledge of the two routes. Straight-line pointing errors and latencies revealed that subjects acquired considerable configurational knowledge about each route and about their relationship, although pointing was slower and less accurate between than within routes. The study demonstrates integration of separately learned spaces in a naturalistic setting, important to theories of environmental learning. It also provides data on learning in vertically aligned spaces and further evidence of the utility of self-report sense of direction as an individual-difference measure.
Work Space Adjustability, Storage, And Enclosure As Predictors Of Employee Reactions And Performance
Authors: O'Neill Michael J.
Published: March 2007

This study develops and tests a conceptual model of the relationships between work space adjustability, storage, and enclosure characteristics, mediating psychosocial perceptions of privacy, distractions, and communication, and outcome measures of satisfaction and performance. Building design and job level variables are also included in the model. A total of 541 managerial and nonmanagerial workers in 14 office buildings located across the United States provided data. Regression and path analyses reveal overall support for the relationships hypothesized by the model. The analyses show that adjustability and storage contribute directly to satisfaction and performance, and indirectly to these outcomes through mediating perceptions of the psychosocial environment. Enclosure played only a minor role in predicting mediating and outcome variables. One aspect of enclosure, type of partition surrounding the work space, predicts communication and privacy, but is only indirectly related to outcome measures. There is a negative relationship between number of floors and density of workers, and some psychosocial perceptions and satisfaction. A positive relationship was found between job level and satisfaction. The study illustrates the value of a multivariate approach to understanding the relative contributions of design variables to worker perceptions and behavior.
Authoritarianism and Attitudes Toward the Environment
Authors: Schultz P. Wesley , Stone William F.
Published: March 2007

Two studies of authoritarianism and environmental attitudes were under-taken. The first, a field study, found the opponents of a proposed riverside power plant to be less authoritarian and more environmentally concerned than supporters of the plants establishment. Overall, right-wing authoritarianism (RWA) correlated -.51 with environmental concern. The second study replicated this finding within a college sample, using a validated measure of environmental concern, the New Environmental Paradigm (NEP) scale. NEP correlated -.54 with RWA. It is concluded that the relationship between authoritarianism and environmental concern is presently strong. Prospective explanations for this relationship revolve around the theoretical nature of authoritarianism.
Toward Integration
Authors: Wapner Seymour
Published: March 2007

The manner in which a particular theoretical approach (the holistic, developmental, systems-oriented perspective) operates to integrate environmental psychology with other subfields of psychology-including clinical, developmental, health, organizational, personality, and social-is described. This serves to advance these and other subfields of psychology and to mitigate the ongoing fragmentation in psychology. Integration is evident in the implications of the assumptions of the perspective for empirical studies, originating largely as theoretical and practical problems for environmental psychology, that have impact on and are of interest to a variety of subfields of psychology.
Precautions Taken Against Lyme Disease at Three Recreational Parks in Endemic Areas of New Jersey
Authors: Hallman William , Weinstein Neil , Kadakia Swati , Chess Caron
Published: March 2007

Visitors to three recreational parks located in Lyme disease endemic counties in New Jersey were surveyed to assess public awareness of recommended precautions against tick bites and how these precautions are being adopted. Interviews were conducted with 178 adult respondents. In open-ended questions, 84% of the respondents could name at least one precaution against Lyme disease; however, only 43% reported taking any precautions. Taking precaution was associateded with the belief that a person they knew with Lyme disease was bitten by a tick while in a place frequented by the respondent, and with the belief that Lyme disease is difficult to cure. Precaution adoption was not associated with gender or with measures of personal experience with Lyme disease, perceived seriousness of the disease, attitudes about and personal experiences with ticks, beliefs that there are infected ticks in the park, or the perceived costs and benefits of taking precautions. These results emphasize the importance of getting people to practice the precautions they already know about, and helping people to recognize situations where taking precautions is appropriate.
The Socioeconomic Context of Exposure and Response to Environmental Risk
Authors: Vaughan Elaine
Published: March 2007

This research examined the association between socioeconomic factors and the risk responses of 437 Mexican immigrant farmworkers chronically exposed to agricultural pesticides. Past explanations for patterns of risk responses have focused on intra-individual factors, and usually have minimized the possible influence of socioeconomic circumstances on adaptation to risk. Immigrant farmworkers from a variety of occupational contexts participated in this investigation and were expected to systematically differ in their response to pesticide exposure depending on socioeconomic circumstances, judgments about the risk situation, and the subjective evaluation of occupational conditions. Analyses revealed that beliefs about the risks of pesticides were not randomly distributed throughout this sample, but varied with socioeconomic factors. For example, workers who were in more limited economic circumstances judged future health effects to be more likely, and believed that safety precautions were less effective. Additionally, socioeconomic circumstances modified the relationship between intra-individual factors and response to risk. The discussion considers several possible links between socio-economic factors and risk adaptation, and implications for environmental policy.
Assessing Beliefs about Lighting Effects on Health, Performance, Mood, and Social Behavior
Authors: Veitch Jennifer A. , Gifford Robert
Published: March 2007

Energy conservation through the adoption of new, energy-efficient technologies will succeed only to the extent that the new technologies are not themselves perceived as risk sources. Previous research has found that beliefs about the health effects of fluorescent lighting predict compact fluorescent lamp use in homes. This paper describes the development and validation of a questionnaire to assess beliefs about the effects of common types of interior lighting on human health, work performance, mood, and social behavior. Principal components analysis of the 32-item Lighting Beliefs Questionnaire revealed 6 interpretable components: Lighting Importance, Brightness, Major Health Effects: Fluorescent Lighting, Minor Health Effects: Fluorescent Lighting, Social Setting, and Daylighting. The questionnaire may be used to explore responses to interior lighting and to discover what beliefs are held by end users. This information will assist in allaying unwarranted fears and concerns about new lighting technologies.
Construction of the Meaning of a Barrio House
Authors: Wiesenfeld Esther
Published: March 2007

This article presents findings of a research carried out in a barrio of Caracas, which aimed at determining the meaning assigned to the houses by their inhabitants. In-depth interviews were conducted with male and female members of the barrio. Results show that the dwelling unit is not conceived separately from its surroundings and neighbors, and its meanings have varied along its transformation from a precarious shack into a consolidated brick house. Three stages corresponding to the building process were identified-initial construction, improvement, and consolidation-each corresponding to the conceptualization of the dwelling as rancho, house, and home, respectively. In addition, the transformation of houses-as a process parallel to both the consolidation of the barrio and the development of a sense of community among its members-grants the house special environmental, psychological, and social meanings and creates great concern in regard to the politics aimed at eradicating rancho neighborhoods.
Aircraft Noise
Authors: Bronzaft Arline L. , Dee Ahern Kathleen , McGinn Regina , O'Connor Joyce , Savino Bartholomew
Published: March 2007

A questionnaire distributed to two groups, one living within the flight pattern of a major airport and the other in a nonflight area, sought to determine whether these groups would respond differently to questions pertaining to noise, health perception, and quality of life issues. Nearly 70% of the residents living within the flight corridors reported themselves bothered by aircraft noise. Aircraft noise, in contrast to other bothersome noises, interfered more frequently with daily activities. Subjects who were bothered by aircraft noise were more likely to complain of sleep difficulties and more likely to perceive themselves to be in poorer health. The study's finding of a possible relationship between noise and adverse health effects might encourage policy makers to enact pending antinoise legislation and to fund further noise research.
The New Affirmative Action
Authors: Malos Stanley B.
Published: March 2007

This study investigates perceptions about the fairness and effectiveness of college admission preferences based on socioeconomic need. In a sample of 137 business students at a multicultural urban university in the western United States, such criteria were perceived favorably in terms of fairness and effectiveness for achieving diversity, helping targeted individuals, and improving institutional quality. However, favorable reactions to race and gender preferences persisted among minorities and women, suggesting that drop-offs in minority enrollments at universities that have replaced such preferences with need-related criteria may correspond to the appearance of reduced institutional commitment to diversity and related affirmative action goals.
Perceived Promotional Opportunities in Veterans Affairs Hospitals
Authors: Lichtenstein Richard , Alexander Jeffrey A.
Published: March 2007

Previous studies using relational demography theory have hypothesized that being demographically dissimilar has a negative impact on individual perceptions of advancement opportunities. The authors investigate whether an organization’s social context, leaders’ characteristics, and geographic location offset, or even reverse, the negative effects of being dissimilar. Data were collected through two surveys: a 1995 survey of 2,252 employees from 139 treatment units in 38 Department of Veterans Affairs (VA) psychiatric hospitals, and a 1999 survey of the 38VA hospitals’ administrative offices. The authors used nested linear regression analysis to test the hypotheses. Unlike previous studies, the results indicate that the more dissimilar an individual is with regard to age andrace, the more positive his or her perceptions of advancement opportunities. They conclude that the equal employment opportunity policies pursued by public sector organizations, such as the VA, may alter the relationship between demographic dissimilarity and perceptions of advancement opportunities.
William G. Allen
Authors: Calloway-Thomas Carolyn
Published: March 2007

In 1983, while at the Library of Congress, working my way carefully through the Black Abolitionists papers in search of materials for my book, What If I Am a Woman: The Rhetoric of Sisterhood and Struggle, 1830-1970, I discovered a lecture titled "Orators and Oratory" by William G. Allen, an African-American professor of rhetoric and belle lettres at Central College, McGrawville, New York. The lecture was delivered before the Dialerian Society of New York on June 22, 1852. Because of its historical value, I believe it should be available as a data base for all scholars, particularly those interested in history and public address. As far as we know, Allen was the first black in the United States to leave a record of intellectual probing into the operation of the ancient art of oratory. Thus scholars who venture to study ancient Greek and Roman history and the mind of nineteenth-century America, should find Allen's deft mastery of these periods delightfully insightful and useful.
Analysis of Laminated Circular Plates
Authors: Schile Richard D.
Published: March 2007

An elasticity solution is obtained to the problem of a thin, laminated, isotropic circular plate under combined transverse and edge loading. The analysis yields an approximate, thin-plate theory which reduces to an exact, closed-form solution when the plate is loaded by edge forces and moments only. The results show that, under edge loading, the stress state is purely biaxial, there being no interlaminar normal or shearing stresses such as are usually present in bulk composite bodies. Further, an estimate of the edge-effect correction which is present when the applied stress distribution does not match the internal stress distribution, discloses no unusual effects due to the laminated structure. Under combined loading, a complex state of in-plane, normal and shearing stresses exists which is coupled through the property variations.
Frequency Effects on the Fatigue of Glass Reinforced Plastics
Authors: Dally J.W. , Broutman L.J.
Published: March 2007

An experimental investigation has been conducted to determine the effects of cyclic frequency on the tensile fatigue characteristics of glass fiber (non-woven) reinforced plastics. A 3-M material was used, XP251, and the fiber orientations thus far studied include cross-ply (0°-90°) and isotropic (-60°, 0°, + 60°). The surface temper atures of the specimens were carefully recorded during the fatigue testing and studied as a function of frequency over the range from 1 cps to 40 cps. The hystersis has also been determined for a single cycle closed loop tension test. Analyses have been conducted and equations developed to predict the temperature distribution due to hystersis heating, the time to achieve steady state at interior points and the steady state surface temperatures. Surface temperatures as high as 265°F have been measured for the isotropic material. The hystersis heat generated in a cyclic fatigue test for a given material is dependent on the product σ 2f. The temperature difference be tween the center of a specimen (thickness-2a) and its surface is a function of (ασ) 2f. The fatigue life of these materials is lowered with increasing cyclic frequency, the effect becoming more pronounced at lower stress levels.
A Strength Prediction of Aggregated Composites
Authors: Riley V.R.
Published: March 2007

This paper is concerned with the development of a theory to predict the strength and failure mechanisms of systems consisting of discrete aggregated particles held together in some fashion. From a practical viewpoint, this would include materials such as plain and asphaltic concrete, and soils. In the case of concrete, the stone particles are held together by a matrix or mortar whereas for soils, the particles are held together by cohesive and/or frictional forces. The theory which is developed appears to show reasonable agreement with observed properties of such composites, and with some preliminary experi ments conducted on an epoxy resin system.
The Laminate Analogy for 2 and 3 Dimensional Composite Materials
Authors: Halpin J.C. , Jerine K. , Whitney J.M.
Published: March 2007

A previously developed laminate analogy for predicting the elastic stiffness and thermal expansion properties of a randomly oriented short fiber composite is extended to include a large class of fiber reinforced composites possessing very complex geometry. In particular, the stiffness and thermal expansion coefficients of short fiber com posites having biased filaments, misaligned filaments, and variable fiber aspect ratios are determined from a laminate analogy. In addition, the laminate analogy is extended to 2 and 3 dimensional woven fabric composites. Theoretical results for the short fiber com posites show excellent agreement with experimental results, while theoretical results for the woven fabric composites are shown to be qualitatively correct.
A Theory of Machining of Fiber-Reinforced Materials
Authors: Everstine G.C. , Rogers T.G.
Published: March 2007

A theory of the machining of fiber-reinforced materials is pre sented. The analysis is restricted to plane deformations of incom pressible composites reinforced by strong parallel fibers. Complete deformation and stress fields, as well as estimates of the forces re quired to maintain continuous machining, are derived. The results apply to both elastic and plastic stress responses.
Stiffness and Strength of Two Glass-Fiber Reinforced Cement Laminates
Authors: Allen H.G.
Published: March 2007

A general description is given of the load-deformation charac teristics in tension, compression and bending of two types of thin cement laminate reinforced with short random glass fibers. Cyclic loading in tension is used to demonstrate that stiffness decreases and residual strain increases as cracking damage accumulates. The dam age depends on the greatest strain previously reached. There is no evidence that the presence of fibers delays the onset of cracking. Bending strains can be predicted by assuming linear strain distribu tions. Bending stress distribution is markedly non-linear. The bending test is an insensitive indicator of the onset of cracking.
Stress Distribution in Bonded Joints *
Authors: Erdogan F. , Ratwani M.
Published: March 2007

The stress distribution in plates bonded through stepped joints is analyzed. The problem is solved under the assumption of gen eralized plane stress. A series of examples are worked out on specific plate geometries and material combinations. The effect of step ends is separately studied. As a limiting case, the solution for bonded plates with a smoothly tapered joint is given, and its results are compared with that of stepped joint.
Macroscopic Fracture Mechanics of Advanced Composite Materials
Authors: Waddoups M.E. , Eisenmann J.R. , Kaminski B.E.
Published: March 2007

The application of classical fracture mechanics to laminated com posites is discussed. A convenient method is presented for predicting the static strength of a flawed specimen. Theoretical predictions are compared with experimental data for specimens containing two types of flaws.
Geometric Dispersion of Acoustic Waves by a Fibrous Composite
Authors: Sutherland Herbert J. , Lingle Richard
Published: March 2007

This study was initiated to examine the transmission of acoustic waves through a fibrous composite whose only dispersive mechanism was geometric. The elastic-elastic composite chosen for study was composed of tungsten wires embedded in an aluminum matrix. This unidirectional com posite was manufactured in two constituent ratios, 2.2 and 22.1 percent by volume of tungsten. The dispersive characteristics of these composites were determined for harmonic waves propagating normal to the axes of the fibers by using standard water-bath techniques with wide-band transducers.

The dispersion data obtained demonstrate that fibrous composites be have as wave filters which selectively transmit or reflect periodic waves. Further, this wave filtering is shown to be a boundary layer phenomenon which can and must be eliminated from dispersion data if it is to be meaningful.
The Vibration of Cantilever Beams of Fiber Reinforced Material
Authors: Abarcar Rene B. , Cunniff Patrick F.
Published: March 2007

Experimental results were obtained for the natural frequencies and the mode shapes of graphite-epoxy and boron-epoxy composite materials having fiber orientations of 0°, 15° , 30° and 90° with respect to cantilever beam axes. Certain elastic constants were experimentally determined and used in a programmed numerical solution in which rotary inertia, trans verse shear, and coupled bending-torsion effects were included. The experi mental results for the 15° and 30° beams gave a clear indication of the interaction between bending and twisting and good agreement was obtained with the numerical results.
Critical Stress Intensity Factors Applied to Glass Reinforced Polyester Resin
Authors: Owen M.J. , Bishop P.T.
Published: March 2007

Geometrically similar double edge-notched fracture toughness speci mens of glass reinforced polyester resin were tested and the critical stress intensity factor ( Kc) determined. For a unidirectional fabric reinforcement with the crack positioned parallel to the fibres Kc did not depend on crack length. For chopped strand mat and balanced weave fabric reinforcement Kc increased with crack length. Using an equivalent yield stress corrected values of K c independent of crack length were determined. Using the corrected Kc values the failure of specimens containing a circular hole was predicted with reasonable accuracy.
Elastoplastic Transverse Properties of a Unidirectional Fibre Reinforced Composite
Authors: Huang Wu-Cheng
Published: March 2007

An approximate theoretical study is made to predict the overall trans verse elastoplastic properties of a unidirectional fibre reinforced composite. Based on the simplest deformation theory of plasticity, the overall trans verse polyaxial elastoplastic constitutive equations for an incompressible composite are obtained. A simple formula is suggested to evaluate the average stress in the fibres. Furthermore, with the prediction of the overall transverse elastic moduli of a compressible composite, the overall trans verse uniaxial stress-strain curve for a compressible composite in the entire elastic-plastic range is obtained. A detailed example is given for a Boron- Aluminum composite. Comparison is made with the experimental and theoretical work done by General Dynamics and Adams respectively.
The Notch Sensitivity of Boron Film Reinforced Composites
Authors: Padawer G.E.
Published: March 2007

The notch sensitivity of boron film ( B/PI) reinforced graphite fiber composites was compared to the behavior of fiber-only material by means of uniaxial tests on tensile coupons with two sizes of holes (.052 and .104 in.) drilled at midgage length, and on undrilled control coupons. The re sults indicated that B/PI additions to graphite fiber laminates reduced the notch sensitivity, while at the same time substantially raising both the tensile strength and the work-to-fracture of the material.
Curing Stresses in Composite Laminates
Authors: Hahn H.T. , Pagano N.J.
Published: March 2007

Analysis of curing stresses in resin matrix composite laminates involves a temperature range over which variation of elastic moduli is appreciable. A method based on total stress-strain-temperature relations is formulated and applied to determine the curing stresses in boron/epoxy composite lam inates. This method is shown to be preferable to the incremental method because the former requires the thermal strains and the stress-strain rela tions only at the final temperature of interest. The use of incremental constitutive equations is also discussed, and it is shown that proper care must be exercised to insure inclusion of interaction terms that have no counterparts in linear theories.
Fracture Mechanical Investigations on Unidirectional Boron-Aluminum and Boron-Epoxy Composites
Authors: Peters Piet
Published: March 2007

The paper presents the results of investigations on DEN (double edge notched) specimens of different crack lengths. With the moire method the shear deformation at the notch tip has been measured. The boron-epoxy composite shows severe shear deformation resulting in matrix cracking parallel to the fibers. Extensive matrix cracking does not occur in notched B-Al. The net fracture strength at crack extension depends on the amount of shear deformation or shear crack formation at the notch tip. This de formation is a function of the crack length. The usefulness of linear elastic fracture mechanics (LEFM) has been investigated with the aid of the net fracture strength at crack extension as a function of the crack length.
Effect of Curing Stresses on the First Ply-failure in Composite Laminates
Authors: Kim R.Y. , Hahn H.T.
Published: March 2007

This paper describes an experimental technique of detecting the first ply-failure in laminated composites using a combination of long strain gages and acoustic emission measurement. The material system chosen for this study is T300/5208 graphite/epoxy laminates of [0/903] S,[±45/902] S and [0/±45/90] S orientations. Each specimen was instrumented with a strain gage and an acoustic emission transducer. In general, the strain gage technique was good for only those cracks that formed under the gage; the cracks in other areas were barely detected by this technique. The acoustic emission technique, however, was very effec tive regardless of crack locations; matrix cracking always manifested itself in a sudden acoustic emission. The reliability of the above techniques was established by visually observing cracks on photomicrographs. Further more, the experimental data for all three types of laminates agreed fairly well with the analytical predictions with and without residual stresses pres ent. Thus, the effect of residual stresses on the first ply-failure has been delineated.
Stress Measurement in Graphite/Epoxy Composites By X-Ray Diffraction from Fillers
Authors: Predecki Paul , Barrett Charles S.
Published: March 2007

The purpose of this work was to measure stresses in graphite/epoxy composites by diffracting X-rays from crystalline filler particles embedded in unidirectional laminates before curing. Particles used were Ag, Nb and CdO, having sharp diffraction peaks at large diffraction angles, θ. The diffraction peaks shift linearly with applied stress in the fiber direction and have stress sensitivities of (2.6, 3.9 and 1.9) X 10-4 deg 2θ/MPa for Ag, Nb and CdO respectively. Elastic strains in filler particles measured by X-rays are proportional to the corresponding composite strains in agreement with the model of H. T. Hahn. Residual strains and stresses in filler particles were also obtained.
Effect of High Load on Statistical Fatigue of Unnotched Graphite/Epoxy Laminates*
Authors: Yang J.N. , Miller R.K. , Sun C.T.
Published: March 2007

The purpose of this paper is to verify experimentally the theoretical model for predicting the effect of the high load (or proof load) on the fatigue behavior of unnotched composite laminates. It is confirmed by the present test program that a specimen is guaranteed to survive a certain number of load cycles as predicted by the theoretical model, after the specimen has survived a high load or proof load prior to fatigue loading. The correlation between the test results and the theoretical distributions of the fatigue life and the residual strength due to the effect of high load is satisfactory.
A Self-Consistent Approach to the Elastic Stiffness of Short-Fiber Composites
Authors: Chou Tsu-Wei , Nomura Seiichi , Taya Minoru
Published: March 2007

The self-consistent approach originally proposed by Hill has been adopted to derive the effective elastic stiffness constants of unidirectional short-fiber composites. The short-fibers are modeled as ellipsoidal inclu sions uniformly distributed in the matrix and the transverse isotropy of the composite has been taken into account. The method of analysis is valid for multi-component systems and hence, applicable to hybrid composites. Comparisons of this analysis with existing theories are made for binary composites.
Experimental Determination of the In Situ Transverse Lamina Strength in Graphite/Epoxy Laminates
Authors: Flaggs Donald L. , Kural Murat H.
Published: March 2007

The uniaxial tensile load at which transverse cracking initiated in the 90 deg. laminae of (0 2/90 n) s, (±30/90 n) s and (±60/90 n) s, n =1,2,4,8, T300/934 composite laminates was determined experimentally using DIB enhanced x-radiography. "In situ" transverse strengths of the 90 deg. laminae corresponding to these loads were then calculated based upon lamination theory predictions including the effects of residual thermal stresses. These in situ strengths, which were as high as 2.5 times the unidirec tional transverse strength, were found to depend strongly on both the 90 deg. laminae thickness and orientation of adjacent laminae suggesting that transverse strength should not be considered as an intrinsic lamina property.
Optimum Elastic Design of A Reinforced Beam
Authors: Tauchert T.R. , Adibhatla S.
Published: March 2007

Optimum fiber distributions in composite elastic beams are investigated us ing the criteria of minimum strain energy and maximum failure load. Ar bitrarily specified bounds are placed upon the specific volume fraction of fibers, and the total volume of fibers available for reinforcing the beam is assumed to be fixed. Numerical results are presented for beams constructed of ordinary and bimodulus composite materials. For the examples considered it is found that significant improvements in both stiffness and strength generally can be achieved through the use of nonuniform fiber distributions.