bluuebunny/crossref_metadata_2025 huggingface dataset:
The Behavioral Effects of Crowding
Authors: Dean Larry M. , Pugh William M. , Gunderson E.K. Eric
Published: March 2007

Crews of 18 U.S. Navy combat vessels rated their living and working conditions aboard ship, including degree of crowding. In order to understand better the behavioral effects of crowding, three different types of measures, corresponding to different definitions of crowding, were constructed. These separate crowding measures correlated uniquely with satisfaction and illness criteria.
Slum Dwellers' and Squatters' Images of the City
Authors: Karan P. P. , Bladen W. A. , Singh G.
Published: March 2007

The images of the city held by slum dwellers and squatters in an Indian city are reported. The study revealed certain spatial regularities in mental images of the city's slum dwellers. The size with which places were perceived and represented on maps declined with increasing distance from the city center; the detail with which different parts of the city were perceived and represented I also declined with distance from the city center. Exactness of mental images, areal range, and locations shown on mental maps varied directly with the ed.ucational level of slum dwellers and squatters and their travel behavior within the city.
Skylab Effects
Authors: Kushnir Talma
Published: March 2007

This article reports the results of a field study in Israel into psychological reactions on the day prior to the fall of Skylab. It was reasoned that knowledge about the impending event would result in emotional arousal to the extent that individuals would appraise Skylab as potentially harmful. It was found that subjective estimates of the probability of injury were associated significantly with state and trait anxiety measures. Anxiety scores and subjective estimates were highest among females, young persons, and individuals with relatively few years of formal education. It was suggested that (a) unrealistically high estimates of risk (given by a large proportion of the sample) may be due to inability to handle rationally probabilistic types of information, and (b) "fear of science and technology" (which may be stronger among individuals with low levels of education) may mediate individual differences in anxieW and in appraisal of risk.
Office Design and Evaluation
Authors: Wineman Jean D.
Published: March 2007

State-of-the-art research in the field is reviewed with emphasis on the impacts of physical environmental quality on worker satisfaction and job performance. The review focuses on three main topic areas: physical comfort and task instrumentality, privacy and social interaction, and symbolic identification. Within each topic area, recommendations are made for planning and design. The article concludes with a discussion of emerging issues in office design and evaluation, including the effects of technological advances on worker satisfac tion and performance.
Perceptions of Appalachia
Authors: Ulack Richard , Raitz Karl
Published: March 2007

This article examines the boundary perceptions and images that three groups have of the Appalachian region. The analysis is based on data gathered from 2366 questionnaires administered to students in 63 colleges and universities located in and adjacent to the Appalachian region. The groups analyzed include the "in-siders" (those who perceive themselves to be from Appalachia), the "cognitive outsiders" (perceive themselves as not from Appalachia but actually reside in the region), and the "residential outsiders" (reside outside region). Results demonstrate that insiders perceive the region to be much larger and in much more postive images than do either of the outsider groups. The practical implications of such findings should include a review of the perceptions of regional residents in defining regional problems, goals, and objectives.
Territories and Territoriality in the Home
Authors: Sebba Rachel , Churchman Arza
Published: March 2007

This research defines human territoriality as a set of attitudes and behaviors in and toward given physical areas and examines its expressions within the home. The authors interviewed 185 adult and child family members individually. The results indicate that the dwelling unit can be described as a territorial model: as a socio-spatial system in which each area has a clear social classification and is characterized by a particular pattern of behaviors and attitudes. Five different types of areas can be identified: individual, shared, public, jurisdiction, and activity areas. These differ in the degree and nature of control possible within them and in their associated behaviors and attitudes. The physical characteristics of the dwelling unit related to control were the size of the shared area and the quality of the boundaries of the individual and shared areas.
Object Relations, Role Models, and Cultivation of the Self
Authors: Rochberg-Halton Eugene
Published: March 2007

Psychoanalytic object relations theory and symbolic interactionism both emphasize the mediating role of representations in the socialization process, yet the relationship between the external environment and the constitution of these representations is quite different in the two approaches. The inherent subjectivism of the Freudian tradition is criticized through an examination of the role of personal possessions in the objectification of the self. Valued material possessions, it is argued, act as signs of the self that are essential in theirown right for its continued cultivation, and hence the world of meaning that we create for ourselves, and that creates our selves, extends literally into the objective surroundings.
Distraction, Privacy, and Classroom Design
Authors: Ahrentzen Sherry , Evans Gary W.
Published: March 2007

Environmental features of elementary school classrooms are examined in relation to distraction and privacy. Teachers' adjustments of their activities to make their settings less distracting are also explored. Classrooms were measured on interior spaciousness, degree of open perimeter, and amenities for private study. A group of 65 students and 13 teachers from 5 schools were interviewed. Environmental influences on distraction, both positive and negative, are particularly prominent among teachers. In addition, teachers' adjustments of curricular activities to prevent distraction are associated with the amount of nonstructural walls in the classroom. Few architectural features are associated with student distraction. Students in classrooms with amenities for private study actually report lower levels of privacy than those students without such classroom amenities. This unexpected finding may be due to limited access to these amenities even when present in the classroom. When they want to be alone, children prefer to be in secluded study areas or corners. Possible explanations for the difference between teacher and student responses are discussed.
Ambient Temperature and Horn Honking
Authors: Kenrick Douglas T. , MacFarlane Steven W.
Published: March 2007

Using a method developed in previous field studies of aggression, this study examined the influence of ambient temperature on responses to a car stopped at a green light. To investigate alternative models of the effects of high temperature on interpersonal hostility, the study was conducted during the spring and summer in Phoenix, Arizona, and included a range on the temperaturehumidity discomfort index up to 1 160. Results indicated a direct linear increase in horn honking with increasing temperature. Stronger results were obtained by examining only those subjects who had their windows rolled down (and presumably did not have air conditioners operating).
Turn Left at the Church, Or Three Miles North
Authors: Ward Shawn L. , Newcombe Nora , Overton Willis F.
Published: March 2007

This study examined how college students give directions from maps, either with maps perceptually available, or after maps had been memorized. Six aspects of direction giving were coded: use of landmarks, use of relational terms, use of cardinal directions, use of mileage estimates, and frequency of omission and commission errors. In accord with predictions, males used more mileage estimates and cardinal directions than did females and made fewer errors. Use of cardinal directions and mileage estimates were rarer, in relation to opportunities to use them, than use of landmarks and relational terms. Correlations among the dependent variables suggested that use of relational terms and use of cardinal directions may trade off, with speakers using one or the other but not both. Results are discussed in the context of the distinction between competence and stylistic preference.
Validity in Environment/Behavior Research
Authors: Kaplan Rachel
Published: March 2007

"Transactional Qualities of Neighborhood Social Networks" (Oxley et al., 1986) provides a thorough analysis of interrelated patterns contributing to neighborhood networks in two seasons. It also provides what appears to be an excellent example of a transactional approach. The authors rightly identify it as a case study. This brief essay raises some questions about the internal and external validity of the Christmas Street study, while also commending the holistic and longitudinal approach that was taken.
Perceived Facilitators and Inhibitors of Work Performance in an Office Environment
Authors: Crouch Andrew , Nimran Umar
Published: March 2007

A descriptive model is presented that identifies characteristics of office surroundings that senior managers believe facilitate and inhibit their work performance. The purposes of the study are twofold. First, to investigate the relative prominence of aspects of office surroundings that managers believe affect their task performance. Second, to determine whether there is a symmetrical relationship between variables inhibiting and those facilitating performance, in other words, whether inhibitors are the negative influence of facilitators. Data for the present study were obtained from a survey of 65 managers asked to name three inhibitory and three facilitative features of their offices. The results suggest that previous research has overemphasized some factors that are relatively unimportant from the viewpoint of office occupants and underemphasized others that do appear important. The lack of symmetry found in some variables influencing performance suggests a possible explanation for some weak relationships found in previous research.
Territoriality and Nonconscious Racism at Water Fountains
Authors: Ruback R. Barry , Snow Jason N.
Published: March 2007

Two studies were conducted to examine the territorial behavior of Blacks and Whites who were intruded on while drinking at a water fountain. In the first study, an experiment, there was a significant interaction of intrusion and race of drinker: White subjects left faster when intruded on by a White confederate than when not intruded on, whereas Black subjects stayed longer when intruded on by a White confederate than when not intruded on. In the second study, observations of same-race and cross-race intrusions revealed that cross-race intruders waited significantly longer before intruding than did same-race intruders, and drinkers stayed significantly longer after intrusions by cross-race than by same-race intruders.
Israeli Palestinian Territorial Perceptions
Authors: Schnell Izhak
Published: March 2007

Israeli Palestinians perceive Israeli national space as a hierarchical system of territories, associated with the different elements of their collective identity. They partition space into meaningful territorial units on eight different hierarchical levels. The three most outstanding levels of the hierarchy are those associated with their national, their Israeli citizenship, and their subethnic identities. Analysis of their attachment to the different territorial units reveals that, although they have an undoubted sense of Palestinian identity, they do not deny their Israeli citizenship. In confronfing the disparity between these two identifies, they seek to overcome the difficulties of complete adaptation to either of them by their attempt to establish for themselves a status of limited freedom of choice and territorial autonomy.
Relations between Environmental Psychology and Allied Fields
Authors: Pacheco Angel M. , Lucca-Irizarry Nydia
Published: March 2007

The evolution of environmental psychology is examined through research aimed at extending the explanatory range and research applications of the holistic developmental systems-oriented perspective. From this series of artides it is evident that environmental psychology, particularly with a constructivist orientation, has much to offer to address critical problems of the discipline as a whole and of subdisciplines such as social, developmental, organizational, health, and educational psychology. The articles in this special issue are reviewed with particular attention to their applied and theoretical psychology. These articles document the potential of the holistic, developmental, systems-oriented perspective for stimulating interprofessional, interdisciplinary collaboration and synergistic relationships across subspecialities in psychology.
The Effect of Commitment on Adoption and Diffusion of Grass Cycling
Authors: Cobern Melissa K. , Porter Bryan E. , Leeming Frank C. , Dwyer William O.
Published: March 2007

Using a design that also permitted an assessment of the extent to which any increase in grass-cycling behavior diffused to the neighbors of treated participants, two types of commitment strategies for promoting residential grass cycling (i.e., not bagging grass clippings) were investigated. Baseline data were collected over a period of 4 weeks to determine which residents in each of three homogeneous neighborhoods bagged grass clippings for curbside pickup. A total of 558 houses observed to bag grass clippings during this period were included as participants in the experiment. Following baseline, the neighborhoods were randomly assigned to one of three conditions. Results indicated that participants who made a commitment to grass cycle and to talk to their neighbors had grass bags present significantly less often than either the commitment-only or control participants. This effect was present during the 4-week intervention period and also was sustained during an immediate 4-week follow-up period and a delayed 4-week follow-up period 12 months later. There also was a diffusion effect in which the neighbors of targeted participants showed significantly more grass cycling than controls, and this effect continued to increase through the 1-year follow-up measure. On the other hand, neither commitment-only participants nor their neighbors differed from controls during any period of the experiment.
A Case Study Investigating the Criminal Activity Among Residents in an Urban Area
Authors: Neild Jill , Paylor Ian
Published: March 2007

This article draws on and adds to the criminological debate surrounding the link between crime and immediate environmental conditions. The article describes and offers analysis of a piece of research conducted by one of the authors in Colne, a small town in Lancashire, England, which sought to examine the propositon that people who reside in a certain locality are more prone to engage in criminal activity. From analysis of press reports of criminal activity, we can see that the incidence of crime moved, during a period of years, from one area of the town to another. The arficle provides an explanation of why this happened and offers comment on the overall issue.
The Link between Recycling and Litter
Authors: Reams Margaret A. , Geaghan James P. , Gendron Raye C.
Published: March 2007

The purpose of our research was to determine whether residential recycling programs introduced an additional benefit-reduced litter. We evaluated the proposition that such programs should impart to participants a heightened environmental awareness and understanding that may encourage them to litter less and/or pick up more accumulated litter. We examined accumulated litter by various types-recyclable litter, recyclable accessories, and nonrecyclable litter-in selected neighborhoods before and after the implementation of the Baton Rouge, Louisiana, curbside recycling program. We found that recyclable lifter decreased significantly after the onset of the program. However, there was no similar decline in other types of litter. Although participants were motivated to discard fewer recyclables and/or pick up more recyclable litter after Implementation of the program, this behavior did not carry over to the proper disposal of nonrecyclable lifter.
Scientific Productivity in Environmental Psychology in Mexico
Authors: Lena María Montero Y López
Published: March 2007

To determine the characteristics of scientific productivity generated within the field of environmental psychology in Mexico, a bibliometric analysis of 143 documents produced in the area from 1960 to 1996 was carried out. The results show a pronounced tendency to generate theoretical-descriptive work and to use adults as study groups. It is argued that it is necessary to develop more research in the area, taking into account more vulnerable groups like the elderly and children. Actions taken and aimed at the strengthening of a communication network for Iberian and Latin American specialists are also described. Finally, emphasis is placed on the convenience of continuing to generate bibliometric, informetric, and scientiometric research showing research trends in environmental psychology.
Residential Satisfaction in Condominios Exclusivos (Gate-Guarded Neighborhoods) in Brazil
Authors: Carvalho Máyra , George R. Varkki , Anthony Kathryn H.
Published: March 2007

Many neighborhoods in contemporary Brazilian cities, known as condomínios exclusivos (CE) (exclusive condominiums), are surrounding themselves with walls or fences and using security gates to control access. By reinforcing spatial differentiation, turning inwards, and avoiding the rest of the city, CEs are dramatically affecting urban form. This article describes our study of an important aspect of the Brazilian CE phenomenon: specifically, satisfaction among CE residents. We used a structured questionnaire to study residential satisfaction in one CE. Not surprisingly, residents are highly satisfied with living in a CE. However, the reasons why they moved into the CE do not coincide with why they like living there now. Three main factors that predict residential satisfaction in CEs are their: a) location, b) safety, and c) unique characteristics.
Subcultural and Cross-Cultural Effects on the Experience of Detached Houses
Authors: Purcell A. T. , Peron E. , Sanchez C.
Published: March 2007

Two experiments are reported using variations in house style as a means of investigating two cognitively based theories of affective experience of the environment and cultural differences in environmental experience. In the first experiment, groups of participants with three differing backgrounds but from the same geographic location (Australia) judged the familiarity, typicality, preference, and interest of six house styles. In the second experiment, two age groups from a different culture and geographic location (Italy) made the same set of judgments about the same experimental stimuli. Systematic similarities and differences were found in the first experiment between the groups as a function of house style. In the second experiment, differences were found between the two age groups of Italian participants. Unexpected similarities were found, however, between both age groups from Italy and the Australian groups. These results are related to the two models of affective experience, and their implications for the models are discussed.
The New Environmental Paradigm and Personal Norms
Authors: Wiidegren Örjan
Published: March 2007

Using data from nationwide representative samples from Sweden and from Sweden's largest environmental organization, proenvironmental behavior is interpreted in the light of Schwartz's norm activation theory. The New Environmental Paradigm (NEP) scale is used as an indicator of awareness of consequences, while inclination to guilt feelings, if harming the environment, is used as an indicator of a personal norm. Regression analysis of proenvironmental behavior and willingness to pay higher prices for environmentally friendly food showed that the indicator of a personal norm was far more strongly correlated to proenvironmental behavior and willingness to pay, respectively, than the NEP scale. Education and income showed hardly any influence on proenvironmental behavior and willingness to pay, whereas gender and age fell somewhere in between. An attempt is made to explain the generally weak correlations between NEP and environmentally relevant variables by pointing out the generally high level of agreement with the NEP items among Swedes.
New Media, New Freedoms, New Threats
Authors: Chalaby Jean K.
Published: March 2007

This article argues that new media often get involved in struggles for new freedoms. The nascent book was involved in the struggle for religious freedom, the public press was engaged in the struggle for political freedom and today the Internet is, in turn, used as an instrument for the advocacy and promotion of new liberties: the freedoms of intimacy. These freedoms are related to needs and preferences derived from identities and lifestyles of communities based on gender, ethnicity, religious affiliation and sexual orientation. As new media help people to extend the frontiers of freedom, public authorities have often attempted to impose controls over them. This article identifies four traditional means of censorship (legal, administrative, violent and economic), and shows that the digital era has brought with it new means of curbing freedom of speech: technology. Finally, this article argues that since the book-burning scenes of the Inquisition, censorship has steadily moved away from demonstrative and restorative justice. The means to curb freedom of speech have become both more efficient and less visible.
Pakistani Television Politics in the 1990s
Authors: Barraclough Steven
Published: March 2007

This article describes the flawed attempts of successive governments in Pakistan to respond to the proliferation of satellite television during the 1990s. The popularity of Indian programming on satellite television is particularly galling, since it challenges the notion of a distinct Islamic identity in the subcontinent - the very ethos of Pakistan's existence. In spite of this challenge, neither the Nawaz Sharif nor Benazir Bhutto administrations were willing to allow news and current affairs on the national broadcaster to move away from their traditional role as the prime promotional vehicle for the government of the day. The availability of permissive programming of satellite television has heightened the sensitivities of conservative Islamic organizations, leading to a backlash against liberal experiments in the depiction of women and gender issues on national television under the Benazir Bhutto government, and a deeply conservative broadcasting agenda under the Nawaz Sharif government.
Comparing Nations in Mass Communication Research, 1970-97
Authors: Chang Tsan-Kuo , Berg Pat Pat , Fung Anthony Ying-Him , Kedl Kent D. , Luther Catherine A. , Szuba Janet
Published: March 2007

The purpose of this article is to assess critically, within the framework of the sociology of knowledge, how we come to know what we know in comparative international communication research. The point of departure is the collective output of comparative international communication enterprise - the published articles in six major communication journals through which theories, methods and findings have been diffused and the cumulated knowledge made possible during the past three decades. A major concern is the general pattern of methodological approaches and epistemological positions as manifested in the existing comparative international communication studies. The common patterns in comparative international communication research include lack of theoretical framework, non-equivalence of concepts and indicators, incomparability of units of analysis and unawareness of Galton's problem.
A `Pernicious New Strain of the Old Nazivirus' and an `Orgy of Tribal Slaughter'
Authors: Wall Melissa A.
Published: March 2007

This study compares US news magazine coverage of conflict occurring in Bosnia and Rwanda. Bosnia's violence was characterized as an aberration for Europeans, while Rwanda's violence was presented as typical of Africans. Coverage suggests that in Bosnia, participants made a logical, albeit evil, decision to commit violence in an attempt to seek revenge for past grievances. In contrast, Rwanda's violence is depicted as having no logical explanation and is portrayed as irrational and so alien from Western understanding as to defy explanation.
Does Watching Court TV `Cultivate' People's Perceptions of Crime?
Authors: Valkenburg Patti M. , Patiwael Marquérite
Published: March 2007

In this study, we aim to determine people's motives for watching Court TV and whether this is related to their perceptions of crime. A questionnaire was administered to a sample of 305 adults (18 plus) in the vicinities of Boston and New York. Inspired by Greenberg's and Rubin's television viewing motives scales, we developed a Court TV viewing motives scale. Using principal components analysis, five Court TV viewing motives were identified: voyeurism, boredom-avoidance, entertainment, relaxation and information. Our results showed that the entertainment motive is the most prominent viewing motive of Court TV, followed by the boredom-avoidance and voyeurism motives. As anticipated, respondents who more often watched Court TV tended to have more negative perceptions of crime in society. However, people who watched Court TV for its informative value in particular showed more negative perceptions of crime. The results are discussed in the light of cultivation theory and uses-and-gratifications theory.
Journalism and the Web
Authors: Deuze Mark
Published: March 2007

The Internet is changing the profession of journalism in a number of ways, which this article looks at in terms of so-called digital, or rather online journalism. This article focuses in particular on the question of if, to what extent and in what respects online journalism differs from traditional journalism. The developments on the Internet in terms of journalism and, more specifically, news on the World Wide Web are presented, leading to a discussion of the three characteristic keywords: interactivity, personalization and convergence. This in itself leads to an analysis of the standards and skills of journalism and journalists online. In conclusion, it is argued that these keywords and journalistic skills and standards closely reflect a contemporary global trend towards community journalism - also known as civic journalism or public journalism - which is an area deserving more study in any analysis of journalism and the Internet.
Creating the “Unfit”: Social Darwinism or Social Triage?
Authors: Glumm Karen , Johnson Jennifer D.
Published: March 2007

Social Darwinism calls for “inequality, survival of the fittest” and not “liberty, survival of the unfittest. ” However, this theory fails to acknowledge that fitness can be a social construction. Social triage argues that bureaucratic decision makers find it inefficient to work with certain groups, and these decision makers sacrifice these groups’ needs in order that others (more beneficial to the organization) receive services. Social triage appears linked to social Darwinism. To favor society’s “most fit” members, it seems necessary to establish “unfit” members. Sacrificing the needs of certain populations seems possible only if fitness can be a social construction. Using a case study of efforts to reform private psychiatric hospitals, we argue that certain hospitals created a supply of “unfit” patients capable of paying the cost of private care, leading to social triage. Although it appeared that social Darwinism was outdated, the connection between these theories may suggest a resurgence in its use.
The Elastic Properties of Three-Phase Composites
Authors: Cohen L.J. , Ishai O.
Published: March 2007

A three-phase particulate composite, consisting of filler and voids within an epoxy matrix, was tested in tension and com pression, covering the volumetric filler- and void-content ranges up to 39% and 52% respectively.
Fibre/Fibre Interaction
Authors: Riley V.R.
Published: March 2007

This paper is concerned with the effect of fibre/fibre interaction on the stress distribution and tensile strength of discontinuous, aligned fibre composites. The stress distribution for a rationalized composite is derived which shows good agreement with an experi ment on a large scale model fibre composite. Expressions are also derived for the tensile strength of the rationalized composite, and these appear to provide reasonable approximations for the strength of practical fibre composites.
Analysis of Anisotropic Plates
Authors: Ashton J.E. , Waddoups M.E.
Published: March 2007

An energy formulation and solutions are presented for the analysis of plane anisotropic rectangular plates with various boundary condi tions. The formulation includes linear theory stability analysis, the calculation of natural frequencies and mode shapes, and analysis of displacement due to lateral loads. In-plane loadings are included in all of these formulations. The Ritz technique is used to find the minimum of energy expressions using a series expansion of beam mode shape functions. Several numerical and experimental results are presented and compared.
The Analysis of Unbalanced Cross-Plied Elliptic Plates Under Uniform Pressure
Authors: Kicher Thomas P.
Published: March 2007

Unbalanced cross-plied laminated plates with bending-membrane coupling are analyzed for the case of an elliptic planform under uniform pressure. Closed form solutions are presented for two cases of mem brane boundary conditions with the bending boundary conditions assumed to be clamped. Comparisons between various approximations and membrane boundary conditions are made for composite plates of glass, Thornel and boron fibers in epoxy matricies. Circular plates are treated as a special case of elliptic plates.
Shock Propagation in a Composite Material
Authors: Torvik P.J.
Published: March 2007

A procedure for calculating the pressure, densities, internal energies and particle velocities behind a plane shock in an infinite composite consisting of alternate layers of two materials or of parallel fibers imbedded in a matrix is presented. The direction of shock propagation is assumed to be parallel to the layers or fibers. Cal culated values of the shock parameters are given for a hypothetical aluminum polymethylmethacrylate composite. Shock speeds in the composite which are lower than the sonic velocity of one of the constituents are found to be possible.
A Model for Stress Wave Propagation in Composite Materials
Authors: Barker L.M.
Published: March 2007

A theoretical model is developed to describe stress wave propaga tion in plate laminate composites. The dispersive effects in the com posite are accounted for by direct analogy with a viscosity effect in the model. The model gives excellent predictions of steady and tran sient wave shapes and velocities, and of the attenuation of short stress pulses. It averages out only the fine structure which results from in dividual reverberations between the plates of the composite. The success of the theoretical model for plate laminate composites should provide a basis for good semi-empirical modeling of the stress wave propagation characteristics of a wide variety of composite materials.
Tensile Strength of Notched Composites
Authors: Cruse Thomas A.
Published: March 2007

Two postulates on the strength of notched laminated composites are compared to experimental data. The first concerns the use of the fracture strength of angle ply composites to estimate the fracture strength of lami nates of several angle plys. The second concerns a macromechanics ex planation of the notch size effect on static strength for circular notches. The results of the comparisons are good but indicate the necessity of more complete and careful experimental data to fully verify any postulated strength theory. However the results shown do indicate that simple analytical models may be used by the designer.
Measurement of the Elastic Moduli of Continuous-Filament and Eutectic Composite Materials
Authors: Sachse Wolfgang
Published: March 2007

Continuous filaments and eutectic composite materials have been treated as homogeneous and orthotropic and transversely isotropic elastic materials, respectively, in stress analysis problems. Based on these assump tions the elastic moduli of boron-epoxy and Al-Al3Ni eutectic composite materials are measured using pulse-echo techniques. The shear wave measurements show that the elastic anisotropy assumed for each material is only an approximation. The measurements are also influenced by defects in the fiber arrangement and, m the eutectic composite, by the presence of a solidification substructure.
Low Velocity Transverse Normal Impact of Graphite Epoxy Composite Laminates
Authors: Mcquillen Edward J. , Gause Lee W. , Llorens Richard E.
Published: March 2007

A theoretical-experimental investigation has been conducted to deter mine the response of composite structural elements to low speed, trans verse impact. Experimental results of this investigation showed that as the velocity of impact is increased it requires less impactor kinetic energy to produce damage.

A structural dynamic response model consisting of a uniform Bernoulli- Euler beam and a rigid impactor mass was employed. Displacement and velocity distributions were assumed as initial conditions and the solution was expanded in the eigenfunctions of the free vibration problem using Galerkins' method.

Good correlation of experimental results with the results of this analyt ical structural dynamic model have been obtained over the velocity range from 0 to 6 m/s.
Hard Object Impact Damage of Metal Matrix Composites
Authors: Awerbuch Jonathan , Hahn H. Thomas
Published: March 2007

The paper presents results on the damage mechanisms in hard object impact and their effect on the residual tensile strength of unidirectional Boron/Aluminum and Borsic/Titanium composites. The ballistic tests were carried out with 0.177" steel spheres impacting at the center of centilever plates over a velocity range of 50 to 4000 ft/sec. The induced ballistic damage and the different failure modes are examined by radiography and SEM, and the post impact residual tensile strength and residual velocity after perforation are studied for both materials.

The damage induced in Boron/Aluminum consists mainly of lateral and axial cracks causing large strength degradation, up to 50 percent of the initial strength. Borsic/Titanium, on the other hand, shows much better impact resistance and the ballistic damage consists of localized plastic de formation and formation of a sheared plug causing strength degradation of 20 percent of the initial strength, as is the case with homogeneous titan ium.

An analytical model based on fracture mechanics can predict fairly well the damage size and the residual tensile strength. Ballistic limit velocity and residual velocity after perforation are shown to be predictable by a model developed for homogeneous metallic plates.
The Fracture Toughness of Boron Aluminum Composites
Authors: Sun C.T. , Prewo K.M.
Published: March 2007

The following paper describes a test and analysis program concerning the fracture toughness of 0° , 90° , 0° /90° and ±45° boron filament rein forced aluminum matrix composites. Two different analytical techniques were used to determine fracture toughness based on the tensile testing of prenotched compact tension specimens over a wide range of ( a/w). It is shown that good agreement exists between these two techniques for both uniaxially and biaxially reinforced material. Comparisons were also made between specimens of two thicknesses and between the behavior of specimens having as-machined and propagating cracks. Values of fracture toughness for boron aluminum are presented and compared with similar data for other engineering materials.
Analysis of the Viscoelastic Response of Composite Laminates During Hygrothermal Exposure
Authors: Flaggs D.L. , Crossman F.W.
Published: March 2007

The linear viscoelastic response of polymeric matrix laminated com posites to hygrothermal exposure is investigated within the framework of lamination theory. Experimentally measured curvature changes in non- symmetric GY70/339 composite laminates during long term exposures to elevated hygrothermal conditions are shown to be accurately predicted by the linear viscoelastic analysis. Application of the analysis is made to prob lems involving 1) dimensional stability and alteration of residual stresses, 2) the strain rate dependence of tensile response, and 3) the effect of residual thermal stress relaxation upon creep in laminated composite plates under mechanically applied loads.
A Note on Specially Orthotropic Laminates
Authors: Caprino G. , Visconti I. Crivelli
Published: March 2007

A particular class of composite laminates is presented, where coupling ef fects are rigorously zero.
Discussion on Criteria for Crack Initiation in the Immediate Vicinity of the Sharp Edges of Dispersed Inclusions
Authors: Tamate O. , Sekine H. , Ozawa Y.
Published: March 2007

The crack initiation in the immediate vicinity of the sharp edges of dispers ed inclusions plays an important role in the strength of dispersion composite materials. The purpose of this work is to duscuss the criteria for crack initia tion in the immediate vicinity of the sharp edges, i.e. the maximum hoop stress criterion, the minimum strain-energy density criterion and the max imum principal stress criterion. These criteria are based on the strength of stress singularity at the sharp edges of inclusions. Experiments are performed by using epoxy resin specimens containing a flat steel inclusion. From the ex perimental results, it is found that the maximum principal stress criterion proposed by the authors is the best one for crack initiation in the immediate vicinity of the sharp edges of dispersed inclusions.
A Fracture Criterion for Edge-Bonded Bimaterial Bodies
Authors: Gradin A.
Published: March 2007

In this paper a fracture criterion for the bond between two different linear elastic materials is proposed. This criterion is based on the singular behaviour of the normal and shear stress in the vicinity of the point of intersection be tween the bond line and the outer boundary.
Fracture Toughness of Unidirectional Glass/Carbon Hybrid Composites
Authors: Thorat Hemant T. , Lakkad Subhash C.
Published: March 2007

The results of fracture toughness of the glass/carbon fibre reinforced epoxy hybrid composites, as expressed by KIC and GIC—the critical stress intensity factor and the critical strain energy release rate respectively, in the crack open ing mode—are presented in the following paper. The tests have been conducted in the 3-point bending configuration for the specimens having a total reinforce ment content of about 55%. The K IC has been evaluated from the GIC and also from the standard expressions normally used for isotropic materials. Similarly, the GIC and KIC have been evaluated by using both Pmax, the maximum load, and PQ, the point of intersection on the load displacement curve with a line having 5% less slope than the slope of the curve at the origin. The trend of the results obtained by these two methods is considerably different particularly with increasing glass content in the hybrids. The values of GIC and KIC obtain ed from PQ exhibit a distinct positive hybrid effect. The hybrids having both the glass and carbon fibres not only have values better than those expected by the rule of mixtures but also better than those of the composite reinforced en tirely by glass or carbon fibres.
Dynamic Analysis of Laminated Shells of Revolution
Authors: Sheinman Izhak , Greif Shoshana
Published: March 2007

A general analytical and numerical procedure is developed for free and forced vibra tion of thin-walled shells of revolution made of arbitrarily laminated orthotropic elastic material. The equations of motion are derived with the aid of Hamilton's variational principle. A numerical solution is obtained by expanding the variables in Fourier series in the circumferential direction, and using conical finite elements in the meridional direction. Several examples involving different shell geometries are considered, in cluding the effects of fiber orientation and boundary conditions.
Interaction of Electromagnetic Radiation with Organic Matrix Composites
Authors: Woo Il Lee  , Springer George S.
Published: March 2007

A model was developed which describes the interaction between linearly polarized transverse electromagnetic waves or isotropic electromagnetic waves and continuous fiber-reinforced organic matrix composites. On the basis of the model, a user-friendly computer code was developed which provides the reflectance, transmittance, total ab sorbed energy, and absorbed energy distribution inside the composite. In order to validate the model, tests were performed using a waveguide measuring the reflectances and transmittances of Fiberite S2/9134B glass epoxy and Hercules AS/3501-6 graphite epoxy composites. The data were compared with the results calculated by the computer code. Good agreements were found between the experimental data and the numerical results. A parametric study was also performed which shows the dependence of the reflectance, transmittance, and absorbed energy on the characteristics of the incident electromagnetic wave, the geometry (composite and coating thicknesses and ply orientation), and the properties of the composite.
Transient Thermal Stress Analysis of a Rectangular Orthotropic Slab
Authors: Wang Hong-Sheng , Chou Tsu-Wei
Published: March 2007

This paper investigates the transient thermal stress problem of a rectangular slab, which possesses both thermal and elastic orthotropy. The slab initially held at a con stant temperature is suddenly subjected to an arbitrary temperature variation along one of its edges. Based upon the solution of transient temperature field, the thermal stress analysis is performed based upon the further development of a displacement- potential approach. The complete stress field has been obtained in closed forms. Numerical results for a typical unidirectional fiber composite have demonstrated high concentration of thermal stresses far exceeding those generated in steady state thermal environment.
The Strengths of Fiber Reinforced Composite Bends
Authors: Chang Fu-Kuo , Springer George S.
Published: March 2007

An analysis is presented for calculating the stresses and strains in bends made of fiber reinforced composites and for estimating the strengths of bends. The stress field is calculated by a finite element method. The strength is predicted using the Tsai-Hill criterion for inplane failure and the Chang-Springer criterion for out of plane failure. Results are presented which illustrate the effects of geometry and ply orientation on the strength and on the mode of failure.
Non-Linear Deformation and Failure Behavior of Carbon/Glass Hybrid Laminates
Authors: Takahashi Kiyohisa , Chou Tsu-Wei
Published: March 2007

An incremental analysis predicting the nonlinear stress-strain relations of laminated composites has been developed. Stress increments corresponding to small increments in the uniaxial tensile or compressive strain are obtained by the laminate theory, in which the anisotropy of fibers and the elastic interaction among fibers have been taken into account. Nonlinear shear stress-strain relations of the constituent laminae are also considered by extending the approach of a preceding paper by the authors. The calculation procedure is modified, in this paper, to take into account the finite strain deformation and the changes of the fiber orientation angles at large deformation. The failure of each lamina is assessed by the maximum stress criterion. The calculated tensile and compressive stress-strain rela tions are compared with experimental results of the carbon/glass hybrid fiber rein forced-filament wound pipes; the reduction in stiffness of the constituent laminae after their failure is investigated. The present analytical method enables us to predict the con stitutive behavior of hybrid composites for uniaxial strain in the range of — 2 % to 3% .
Effective Thermal Conductivity of Composites with Interfacial Thermal Barrier Resistance
Authors: Hasselman D.P.H. , Johnson Lloyd F.
Published: March 2007

A modification of the original theories of Rayleigh and Maxwell permitted the deriva tion of expressions for the effective thermal conductivity of composites consisting of a continuous matrix phase with dilute concentrations of dispersions with spherical, cylin drical and flat plate geometry with a thermal barrier resistance at the interface between the components.
Free and Forced Nonlinear Dynamics of Composite Shell Structures
Authors: Wu Y.C. , Yang T.Y. , Saigal Sunil
Published: March 2007

Natural frequencies and forced responses of thin laminated composite shells of general form are investigated using a high-order curved shell finite element. The effect of geo metric nonlinearity is included in the determination of the forced responses which are ob tained using Newmark's numerical integration scheme. A class of shell problems which are general with respect to geometry; boundary conditions; number, stacking sequence, and angle of orientation of the lamina; and load function can be solved using the present formulations. Numerical results and their comparisons with existing solutions are pre sented for cylindrical shells, shells of positive and negative Gaussian curvature, spherical caps, and shells of translation with different boundary conditions.
Effect of Plasticity on Free Edge Stresses in Boron-Aluminum Composite Laminates
Authors: Sun C.T. , Chen J.K.
Published: March 2007

A general orthotropic yield criterion that is quadratic in stresses in conjunction with the incremental flow theory of plasticity was used to analyze free edge interlaminar stresses in composite laminates. The growth of plastic zones and the distributions of interlaminar stresses were studied using a pseudo three-dimensional finite element method. Results for [0/90] s, [90/0] s, and [45/-45] s Boron-Aluminum metal matrix composites were pre sented. It was found that the inclusion of plasticity could significantly alter the inter laminar stresses.
Crack Propagation Modes in Particulates: A Study Approaching Reality
Authors: Theocaris P.S. , Demakos C.B.
Published: March 2007

Cracked composite plates with spherical glass inclusions bonded inside a flexible matrix made of an epoxy polymer were subjected to impact. The effect of the inclusions on an edge crack propagating inside the plate was investigated, as well as the interaction of two skew-parallel edge cracks propagating in the same composite plates. It was found that gen erally the inclusions repel the cracks in both cases studied, and they are responsible for the bifurcations of the propagating cracks. A crack arrest phenomenon also appeared at the neighborhood of inclusions, which was followed by a subsequent emission backwards of Rayleigh waves. Moreover, the skew-parallel cracks always attracted each other, although the inclusions provoked the cracks to deviate from their initial paths. For the study of crack propagation inside these composite plates the optical method of caustics was used for the evaluation of the crack velocities, as well as the instantaneous values of the dyanmic stress-intensity factor Kr(t) and K rr(t) at the crack tips. Interesting results were derived concerning the variation of the velocities and SIFs of the cracks inside particulate- filled plates.