bluuebunny/crossref_metadata_2025 huggingface dataset:
The ‘Long March’ of the Management Modernizers: Ritual, Rhetoric and Rationality
Authors: Carter Chris , Mueller Frank
Published: July 2003

This article deals with a transition process from a professional engineering archetype to a modernizing managerialist archetype in a British electricity utility. This took place in the context of the substantially changing utility sector characterized by privatization, the introduction of efficiency targets, the introduction of a regulatory system, the prospect of mergers and predatory takeovers. The high-flying rhetoric of modernizing managerialists needs to be seen in the context of institutional templates, which carried substantial mimetic legitimacy, in particular programmes such as total quality management, teamworking and job redesign. They provided a basis to displace entrenched engineering rituals, and establish a new ‘dominant rhetoric’. One reading ascribes such projects as striving towards objectified and technocratic organizational improvements - the modernizers’ rhetoric. An alternative reading is one that problematizes such an understanding by instead drawing attention to the largely ceremonial and rhetoric intensive nature of modernizing managerialism - the critics’ rhetoric. A third perspective is provided by engineers who were fighting a largely rearguard action, as professional expectations emphasizing engineering safety were gradually losing force, but remained in sedimented form. The rhetoric intensive practice of talking ‘spin’ and engaging in elaborate rituals may well, whether in political or in organizational life, lead to critical, and sometimes cynical responses. In this article we highlight the way in which the scripts of ceremonialism, reformism and cynicism have played out among managerial and professional groups in the organization.
A Qualitative Investigation of Perceived Executive Ethical Leadership: Perceptions from Inside and Outside the Executive Suite
Authors: Treviño Linda Klebe , Brown Michael , Hartman Laura Pincus
Published: July 2003

Senior executives are thought to provide the organization’s ethical ‘tone at the top’. We conducted an inductive interview-based study aimed at defining the perceived content domain of executive ethical leadership. We interviewed two types of key informants - corporate ethics officers and senior executives - about executive ethical leadership and then a contrasting category we labeled ‘ethically neutral’ leadership. Systematic analysis of the data identified multiple dimensions of ethical and ethically neutral leadership. The findings suggest that ethical leadership is more than traits such as integrity and more than values-based inspirational leadership. It includes an overlooked transactional component that involves using communication and the reward system to guide ethical behavior. Similarities and differences between ethics officers’ and senior executives’ perceptions also led to insights about the importance of vantage point and social salience in perceptions of executive ethical leadership. In order to be perceived as an ethical leader by those outside the executive suite, the executive must engage in socially salient behaviors that make the executive stand out as an ethical figure against an ethically neutral ground.
Nothing Clinical, Just Business? Reflections on Psychoanalytically Grounded Organizational Diagnosis and Intervention
Authors: Driver Michaela
Published: July 2003

The purpose of this article is to explore psychoanalytically grounded approaches to organizational consultation. The article draws on existing literature as well as personal interviews with several contributors in the field to articulate certain critical concerns over psychoanalytically grounded organizational study and intervention. These include the inappropriate analyzing of clients, non-systemic interventions, wild analysis and collusion. The article examines in detail how contributors in the field see the work they carry out and how they respond to various criticisms. It is suggested that the parameters of clinical psychoanalysis may be used as the basis for a constructive dialog in the field aimed at addressing critical concerns and developing both theory and applications.
Understanding Social Loafing: The Role of Justice Perceptions and Exchange Relationships
Authors: Murphy Susan M. , Wayne Sandy J. , Liden Robert C. , Erdogan Berrin
Published: July 2003

We proposed that the social exchange relationships individuals form in the workplace would mediate the relation between perceptions of interactional and distributive justice and social loafing. Specifically, we argued that both leader-member exchanges (LMX) and team-member exchanges (TMX) would mediate the relation between interactional justice and social loafing, and that LMX would mediate the relation between distributive justice and social loafing. In a field study, 124 manufacturing employees responded to questionnaires and their immediate supervisors were interviewed. The results indicated significant relationships between interactional justice and LMX, and between interactional justice and TMX. LMX, but not TMX, was negatively related to social loafing. Distributive justice was not significantly related to LMX. Thus no support was found for LMX as a mediator of the relationship between distributive justice and social loafing.
Does Privatization Create a ‘New Breed’ of Managers? A Study of the UK Railway Industry
Authors: Pendleton Andrew
Published: July 2003

The article enquires whether privatization leads to an influx of managers with different characteristics, attitudes, and perspectives from incumbent state enterprise managers, as has been widely suggested in studies of privatization in both economics and sociology. These questions are addressed with reference to an empirical study of managers in several companies in the UK privatized railway industry. The characteristics and views of new entrants are compared with those of incumbents. Clear differences in demographic and career characteristics are observed between the two groups, but there is little difference between them in attitudes and perspectives on management. The main exception is in the area of labour-management relationships. These findings suggest that accounts by scholars and practitioners overstate the differences between the two groups of managers.
Promoting Role Breadth Self-Efficacy Through Involvement, Work Redesign and Training
Authors: Axtell Carolyn M. , Parker Sharon K.
Published: July 2003

This article examines the influence of organizational practices on role breadth self-efficacy (RBSE); a person’s confidence in performing proactive, interpersonal tasks that go beyond traditional boundaries. A longitudinal study showed that increased task control, membership of an active improvement group, and breadth of training were associated with increased RBSE. Providing a stronger basis for causal inference, membership of active improvement groups at Time 1 also had a positive lagged effect on later RBSE. These findings support the proposition that RBSE can be enhanced via organizational intervention. The study also showed that, after controlling for greater involvement, job enlargement had a negative lagged effect on RBSE. This suggests the potential detrimental consequences of enlarging jobs without also expanding employees’ autonomy and influence.
Ethical Choice in Managerial Work: The Scope for Moral Choices in an Ethically Irrational World
Authors: Watson Tony J.
Published: July 2003

Ethical and moral aspects of the work of managers are given less direct attention in the literature than we might expect given the growing attention being paid to business ethics more generally. Theoretical analysis together with an account of one self-avowedly ethically sensitive senior manager is used to argue that corporate managers may be less ‘morally mute’ than they are often alleged to be. Managers - ‘strategic’ ones at least - necessarily deal with ethically sensitive pressures coming from the various constituencies with which an organization strategically exchanges. In this, there is scope for individual managers (who are, themselves, resource-dependent constituencies) to bring to bear their personal ethical preferences on decisions and to mediate corporate priorities. The extent to which managers generally recognize this scope and exploit opportunities to adopt ‘ethically assertive’ as opposed to ‘ethically reactive’ orientations is an important question for detailed research.
Your Money or Your Life? Psychotic Implications of the Pension Fund System: Towards a Socio-Analysis of the Financial Services Revolution
Authors: Sievers Burkard
Published: July 2003

The present Anglo-American pension funds system is based on totally different images of man, society, and social relatedness than the traditional social security systems and retirement schemes characteristic of welfare states in many European countries. This article is guided by the working hypothesis that the pension fund system, because of its inherent defenses against persecutory and depressive anxieties, is based on psychotic dynamics. Participation in the pension fund system encourages a psychotic dynamic; the expected pension after retirement is seen to protect one from a ‘miserable’ way of life, from deprivation, from annihilation and feelings of dependency, gratitude, love, and guilt. As people increasingly strive for an affluent retirement, commoditized money nurtures the illusion that the more money one accumulates the more certain death will be kept away. It further will be argued that the psychotic dynamic inherent in the pension funds system is not limited to those who invest in the funds, but further finds an expression or ‘resonance’ in the organizations that manage the funds and their respective role holders. Money paid into a pension scheme serves - in addition to its ‘pecuniary’ function - as a ‘conductor’ of psychotic anxieties. As a consequence, pension funds have become the main players in a kind of global marshalling yard where underlying anxieties are transferred and shifted in various ways. Loaded with their customers’ expectations and anxieties about adequate pensions after retirement, pension fund organizations tend to maintain and spread a globalized collusion of psychotic thinking.
The Use of Personality Typing in Organizational Change: Discourse, Emotions and the Reflexive Subject
Authors: Garrety Karin , Badham Richard , Morrigan Viviane , Rifkin Will , Zanko Michael
Published: July 2003

This article is based on a study of an organizational change program that sought to alter employees’ self-perceptions, emotions and behavior through the use of the Myers-Briggs Type Indicator, a popular personality-typing tool. The program affords an opportunity to explore the various ways in which discourses advocating personal and organizational change work through employees’ subjectivity. We argue that theoretical approaches that view the targets of such programs as passive - as either ‘colonized’ or constructed by discourses - fail to capture the complex and contradictory nature of organizational control, and subjects’ changing positions within it. Drawing on symbolic interactionism, we argue that the power of discourses is mediated through an active, reflexive, and often emotional engagement on the part of individuals. Through their involvement, employees variously reproduce, resist or reconfigure power relationships which, during organizational change, are themselves unstable and inconsistent.
The Complexity of Improvisation and the Improvisation of Complexity: Social Science, Art and Creativity
Authors: Montuori Alfonso
Published: July 2003

The concept of improvisation has become increasingly popular in the discourse of organizational theory. This paper explores several aspects of improvisation, in the context of musical, organizational, and everyday activities, in order to address some of the philosophical and practical issues relevant to this emerging interest. Connections are made between the modernist concept of organization and scholarly inquiry, and postmodern or complexity-based approaches that stress creativity as an emergent property of the relationship between order and disorder. It concludes by suggesting that the study of improvisation demands a profound immersion in (inster-)subjectivity, emotions, time, aesthetics, performance, and social creativity, none of which have traditionally been the focus of organization and management studies, or the social sciences in general. It also suggests that the practice of social sciences itself should reflect upon, and attempt to incorporate these elements.
Consulting as a Liminal Space
Authors: Czarniawska Barbara , Mazza Carmelo
Published: July 2003

The growing literature on management consulting views consultants as allies of management, in temporary positions of power. This article attempts to complement this perspective by assuming a metaphor of consulting as a liminal space. Liminality is a condition where the usual practice and order are suspended and replaced by new rites and rituals. We build on the anthropological analyses of Arnold van Gennep and Victor Turner to find theoretical support for the idea of liminality as applied to the consulting activity. This article is based on our experience as consultants and observers. It collects on-the-job reflections - ours and those of other consultants we have met. These participating observations support the suggestion that consulting can be represented as a liminal space for both consultants and their client organizations.
Workaholism: Its Definition and Nature
Authors: Harpaz Itzhak , Snir Raphael
Published: July 2003

The term ‘workaholism’ is widely used, but there is little consensus about its meaning, beyond that of its core element: a substantial investment in work. Following Snir and Zohar, workaholism was first defined in the present study as the individual’s steady and considerable allocation of time to work-related activities and thoughts, which does not derive from external necessities. Subsequently, it was measured as time invested in work, while controlling the financial needs for this investment. The relation between workaholism and possible attitudinal (meaning of work indices), demographic (gender, marital status), and situational (occupation type, employment sector) variables was examined through two representative samples of the Israeli labor force. The following predictor variables were significantly related to workaholism: work centrality, economic orientation, occupation type, employment sector and gender. From those variables, gender was found to be the strongest predictor - that is, men, in comparison with women, have a higher likelihood of being workaholics. Moreover, married women worked fewer hours per week than unmarried women, while married men worked more hours per week than unmarried men. The theoretical contribution of the above findings, and of the other study’s findings, to the understanding of workaholism is discussed.
Burnout and Intersubjectivity: A Psychoanalytical Study from a Lacanian Perspective
Authors: Vanheule Stijn , Lievrouw An , Verhaeghe Paul
Published: July 2003

This article examines the intersubjective process connected with burnout. On the basis of qualitative research data we investigate to what extent Lacan’s model of intersubjectivity enables us to under-stand the burnout process and to differentiate between people who suffer from burnout and those who do not. We first outline Lacan’s theory of intersubjectivity through a discussion of the dialectical master/slave relationship and the difference between imaginary and symbolic interactions. This model is then tested against the interview material of 30 special educators drawn from the results of a wider random sample survey of 765 respondents in response to a burnout questionnaire. We found that Lacan’s distinction between imaginary and symbolic functioning allows us to make a difference between high and low scorers. High scorers - among whom two subtypes can be distinguished - function mainly in an imaginary way. Among low scorers we similarly found two subgroups - one that interacts symbolically and one that interacts imaginarily, but in which latter case environmental factors are found to have a protective function.
Nonresponse Rates to Organic Questionnaire Items as Evidence of Parallel Processes during Organizational Diagnosis
Authors: Alderfer Clayton P. , Simon Andrew F.
Published: July 2003

Using the concept of parallel processes, this study frames nonresponse rates to organic questionnaire items as indicators of authority relations within the organization. Based on information obtained during entry, an eight-person team conducting an organizational diagnosis with a state agency measured employee attitudes toward management training, their own supervisory relationship, and senior management. Consistent with the hypotheses, the study found nonresponse rates varied by respondents’ hierarchical level and questionnaire topic. There also was an interaction between employee job level and questionnaire item response rate. Highest nonresponse rates occurred among hourly employees addressing questions about senior management. In parallel fashion, higher ranking employees showed more favorable attitudes toward management training, supervision, and senior management. The findings point to the potential scientific benefit of treating nonresponses to measuring instruments as information about the organization rather than just as methodological artifacts affecting the validity of the findings.
Values and Organizational Change
Authors: Amis John , Slack Trevor , Hinings C. R.
Published: July 2003

The role of values in determining how organizations are structured and operated has become an increasingly important area of study. As yet, however, little work has explored the way in which values affect the change process. Drawing on insights from the institutional theory, change, and values literatures, this article presents a set of propositions that explore the change-values relationship. The propositions were examined using real-time data collected over a 12-year period from a set of Canadian amateur sport organizations undergoing pronounced institutional change. It was found that organizations that contained members who held values congruent with the prescribed changes were able to successfully engage in the transition process. Conversely, those organizations with members who opposed the change entered into a period of largely superficial conformity, mainly in response to certain coercive pressures, but ultimately reverted to designs more consistent with the values held within the organization.
The Merger of ACE and CARE
Authors: Baptiste Roland G.
Published: July 2003

This case study examines the merger of ACE and CARE, two Caribbean banks. The merger was of the horizontal type, and ACE employed a “democratic conqueror strategy. ” The merger was a financial success, and the human resource management problems experienced were resolved without any serious deterioration of labor-management relations. These successes may be attributable to the length of the period over which the merger occurred, the democratic strategy adopted, and the attempt to create a new culture for the merged entity.
“The Best Place to Be”
Authors: e Cunha Miguel Pina
Published: July 2003

Using a case study of an integrated information technology services firm, the author examines how the interplay between culture, structure, and leadership is managed in order to build control and employee loyalty. The author focuses on the salient features of the case, namely that a high-profile culture combines with a low-profile leadership and with minimal structuring to create a vibrant and loyalty-generating organizational environment. The author proposes that these processes are effective because they reinforce one another. It is their articulation, not their existence, that acts both as an unobtrusive control mechanism and as an employee loyalty–generating process, fulfilling the needs of both the organization and its professionals.
Composites with Embedded Optical Fibers at Structural Details with Inherent Stress Concentrations
Authors: Skontorp Arne
Published: July 2003

A recurring issue relating to composites with embedded optical fibers is the concern that optical fibers will act as unintended crack initiators leading to untimely failure of the host structure. Previous studies have shown that there is little or no reduction in load-carrying ability as long as an optical fiber is embedded between similar plies and the optical fiber is, predominantly, in the fiber direction of these plies. However, most composite structures also contain structural details with inherent stress concentrations, and a need exists to investigate whether the introduction of embedded optical fibers into these regions will affect the load-carrying ability. In the present study, one composite lay-up containing ply-drops and one bolted joint configuration were studied. Results indicate that embedded optical fibers will not in general affect the structural integrity, as they did not initiate failure.
Fatigue Life Estimates in Woven Carbon Fabric/Epoxy Composites at Non-Ambient Temperatures
Authors: Khan Rehan , Khan Z. , Al-Sulaiman F. , Merah N.
Published: July 2003

The influence of temperature on fatigue resistance of Plain Weave Woven CFRP isexamined. The 8-ply laminateswere obtained from epoxy resin prepreg fabric layers stacked in two different sequences, producing unidirectional [0]8 and angle plied [0, 0, 45, −45]s orientations. The fatigue tests were carried out at −20, 0, 24, 100 and 150°C. It wasfound that there wasno change in sequence of damage eventsbut duration of each event and hence cumulative damage rateswere different at different temperatures. The fatigue life at elevated temperature was found to decrease with increasing temperature but decreasing temperature below ambient conditions caused an increase in fatigue life for both classes of woven laminates. An analytical model based on stiffness degradation during cyclic loading, which isused in fatigue life prediction of CFRP at ambient temperature conditions has been successfully employed to estimate fatigue lives of WCFRP at non-ambient temperatures. A parameter Dcritical, which isa function of testing temperature, and represents the least stiffness value in modulus degradation curve, was introduced. Estimates of fatigue lives were compared with experimentally determined fatigue lives. Reasonably good correlation has been obtained between calculated and experimentally determined values of fatigue at all test temperatures considered in the present investigation.
Modeling and Characterization of Bending Strength of Braided Fabric Reinforced Laminates
Authors: Huang Zheng-Ming
Published: July 2003

The purpose of this paper is to model and characterize the ultimate bending strength of laminated braided fabric reinforced composites.An experimental procedure has been carried out to measure the load–deflection relationships of laminated beams made from multilayers of diamond braided carbon fabrics and an epoxy matrix subjected to 4-point bending.Two braiding angles, i.e. 5° and 15°, with different fabric arrangements have been utilized.The failure mechanisms of the fabric laminae within the laminate were realized with the help of a resin combustion and fabric peeling technique.It was found that the failure of the beams always initialed from the top surface and that some layers including the bottom surface did not fail when the maximum lateral load was applied.This shows that the ultimate bending strength of a laminate generally does not correspond to the stress level at which the last-ply failure takes place.Thus, in addition to the maximum normal stress failure criterion incorporated with the present modeling approach, a critical deflection or curvature condition is also necessary in order that the ultimate bending failure can be identified.The overall load shared by a lamina in the laminate is two-dimensional (2D), and is determined by virtue of the classical lamination theory.However, the lamina local response within its ply system is three-dimensional (3D) due to a complicated fibrous preform contained, and is analyzed based on the bridging model.Only the individual fiber and matrix properties and the laminate geometric parameters are required, which can be easily determined/measured beforehand.Using measured beam deflection corresponding to which the ultimate bending load occurred as the additional controlling parameter, the predicted load–deflection curves up to the third-ply failure for a number of the braided carbon–epoxy laminates agree reasonably well with the experimental results.
Time–Temperature Dependence of Tensile Strength of Unidirectional CFRP
Authors: Nakada Masayuki , Miyano Yasushi , Kinoshita Masaya , Koga Ryuju , Okuya Tsuguyuki , Muki Rokuro
Published: July 2003

We have observed in our previous works [Miyano, Y., Nakada, M., Kudoh, H. and Muki, R. (1999). Prediction of Tensile Fatigue Life under Temperature Environment for Unidirectional CFRP, Advanced Composite Materials, 8: 235–246; Miyano, Y., Nakada, M., Kudoh, H. and Muki, R. (1999). Determination of Tensile Fatigue Life of Unidirectional CFRP Specimen by Strand Tenting, Mechanics of Time- Dependent Materials, 4: 127–137] that the tensile strength along the longitudinal direction of unidirectional carbon fiber reinforced plastics (CFRP) is highly time–temperature dependent. In this paper, we propose a prediction scheme of the master curve for the tensile strength of CFRP under constant strain rate (CSR) loading; we extend Rosen’s analysis [Rosen,B.W. (1964). Tensile Failure of Fibrous Composites, AIAA J., 2: 1985–1994] for tensile failure of unidirectional fibrous composites with elastic matrix to CFRP with viscoelastic matrix by making two modifications. First, we replace the ineffective length with the recovery length over which the interfacial shear stress is uniform. Second, we substitute the value of shear relaxation modulus at the time of failure for shear modulus in Rosen’s formula after the first modification. The shear relaxation modulus of polymer in the CFRP was estimated from the tensile storage modulus of CFRP obtained from the dynamic double cantilever beam under various frequencies and temperatures. The tensile test for unidirectional CFRP was carried out at various loading rates and temperatures; a smooth curve was drawn to represent inherently scattered strength data for each temperature. The master curve for CFRP strength together with the shift factors was obtained. The predicted master curve for tensile strength using an assumed value 7.5 for Weibull shape parameter of fiber strength captured the test data for CFRP (T400 and Epikote 828) adequately for small to medium time but poorly for large time.
Degradation of Carbon Fiber-Reinforced Epoxy Composites by Ultraviolet Radiation and Condensation
Authors: Kumar Bhavesh G. , Singh Raman P. , Nakamura Toshio
Published: July 2003

The degradation of an IM7/997 carbon fiber-reinforced epoxy exposed to ultraviolet radiation and/or condensation has been characterized. Based on observations of physical and chemical degradation it has been established that these environments operate in a synergistic manner that causes extensive erosion of the epoxy matrix, resulting in a reduction in mechanical properties. Matrix dominated properties are affected the most, with the transverse tensile strength decreasing by 29% after only 1000 h of cyclic exposure to UV radiation and condensation. While, the longitudinal fiber-dominated properties are not affected for the exposure durations investigated, it has been noted that extensive matrix erosion would ultimately limit effective load transfer to the reinforcing fibers and lead to the deterioration of mechanical properties even along the fiber dominated material direction.
Thermal Effects on the Pin-Bearing Behavior of IM7/PETI5 Composite Joints
Authors: Walker Sandra P.
Published: July 2003

Thermal effects on the pin-bearing behavior of an IM7/PETI5 composite laminate are studied comprehensively within this paper. Pin-bearing tests of several lay-ups at the operating temperatures of −129, 21, and 177°C are conducted to generate data on the effect of temperature changes on the pin-bearing behavior of the IM7/PETI5 material. A unique computational study investigating the factors influencing pin-bearing strength is performed for the [90,0]8s lay-up. A detailed three-dimensional finite element model is developed including the modeling of resin layers between plies in the laminate with a pin hole. Using a previously established technique, the pin-bearing problem was modeled assuming a rigid frictionless pin and restraining only radial displacements at the hole boundary. An original three-dimensional solution, where thermal residual stresses were combined with the state of stress due to pin-bearing loads was evaluated. The presence of thermal residual stresses were observed to intensify the interlaminar stresses predicted at the hole boundary in the pin-bearing problem. Furthermore, the research shows that changes in material properties drives pin-bearing strength degradation with increasing temperature. The thermal residual cure stresses then somewhat affect the extent that the pin-bearing strength changes with temperature. In general, thermal residual stresses were determined to be significant in affecting pin-bearing strength.
Fiber–Matrix Interfacial Failure Characterization Using a Cruciform-Shaped Specimen
Authors: Tandon G. P. , Kim R. Y. , Bechel V. T.
Published: July 2003

In this study, a cruciform-shaped test specimen is utilized to characterize the fiber–matrix interface under transverse and combined (tensile and shear) loading. We first present an overview of past references of how the cruciform geometry is optimized to promote interfacial failure. We then discuss a modification of the cruciform specimen where face-sheets are adhesively bonded to reinforce the sample. These face-sheets serve a twofold purpose, namely, to prevent premature failure in the fillet region and to encourage debond initiation at the center of the gage length. Finally, an off-axis cruciform geometry, in which the wings of the cruciform sample are inclined at an angle with respect to the loading direction, is introduced to characterize the fiber–matrix interface under combined transverse and shear loading. Using the measured value of applied stress at debond initiation, and the evaluated stress concentration factor at the fiber–matrix interface, a mixed-mode failure envelope is then constructed in the normal-shear stress space, and a quadratic failure criterion is proposed.
Micro-Mechanical Modeling of Polymer Based Unidirectional Composites: Use of Bulk Properties of Matrix with the Smeared Crack Model
Authors: Jadhav Virendra R. , Sridharan Srinivasan
Published: July 2003

Traditional approach to micro-mechanical modeling uses in situ properties of ingredients, which are so fitted as to match predictions of the micromechanical analysis with the experimental in-plane shear response of a lamina for a particular value of fiber volume fraction. In situ properties thus derived, cannot, in general, be used with a different fiber volume fraction or a different micromechanical model. The study presented here is based on the premise that micromechanical models should be transparent and rational tools for obtaining composite properties. Therefore, an attempt is made to characterize the composite from the actual properties of the ingredients and accounting for the presence of thermal residual stresses, shear softening and micro cracking in the matrix throughout the loading history. Experimental comparisons show that a micro-mechanical model with a realistic representative volume element (RVE) and diligent accounting of matrix behavior provides good bounds on experimental response with consistent accuracy, when bulk material properties are used.
Direct Numerical Simulation of Composite Structures
Authors: Kim Seung Jo , Lee Chang Sung , Yeo Hea Jin , Kim Jeong Ho , Cho Jin Yeon
Published: July 2003

Fiber-reinforced composites are not chemical compounds but physical mixtures of fiber and matrix, and the constituents are bonded together. Therefore, it is natural and essential to adopt a full microscopic model and directly analyze the model with no assumptions for local deformation or local loading conditions, in order to understand and predict not only the averaged or homogenized behaviors but also the detailed microscopic behaviors of composite structures. However, in spite of the necessity, full microscopic models of composite structures have rarely been dealt with, mainly because of their difficulties arising in the actual computation of the finite element model with immense degree of freedoms.

In this work, to overcome the difficulties and analyze full microscopic models of composite structures, an efficient parallel multifrontal solver, which can utilize distributed computing resources unlimitedly, is developed and applied to the Direct Numerical Simulation (DNS) of composite structures. Using the developed code, feasibility studies are carried out to observe whether or not the proposed solver is adequate for the DNS of composite structures, such as in parallel performance and others. As an example of DNS, virtual experiments are carried out, where material constants are directly obtained through DNS. Comparisons with previous experimental and theoretical results show the promising possibility that the present virtual experiments by the DNS of composite structures can be an alternative way to obtain material constants without expensive real experiments. Additionally, a microscopic model with defects is also analyzed and compared with a perfect model to validate the potential of the DNS in dealing with irregularity of microscopic models of composite structures coming from imperfection. The examples show the future direction of analysis and design of composite structures as well as the usefulness of the proposed DNS methodology.
Analytical and Experimental Studies of the Debonding of Stitched and Unstitched Composite Joints
Authors: Glaessgen E. H. , Raju I. S. , Poe C. C.
Published: July 2003

The effect of stitches on the failure of a single lap joint configuration was determined in a combined experimental and finite element study. The experimental program was conducted to determine debond growth under static monotonic loading. The stitches were shown to delay the initiation of the debond and provide load transfer after total debonding of the lap joint. The experimentally determined debond length versus applied load was used as an input parameter in the finite element analysis of both stitched and unstitched configurations. The strain energy release rates at the debond front were calculated using plate elements. Discrete nonlinear spring elements were used to model the stitches and multipoint constraints were used to model the contact problem. Models of the unstitched configuration showed significant values of mode I and II strain energy release rates across the width of the joint and showed that mode III is zero at the centerline but increases near the free edge. Models of the stitched configuration showed that the stitches were effective in reducing the mode I component to zero, but had less effect on modes II and III.
Nonlinear Viscoelastic Finite Element Analyses of Thermosetting Polymeric Composites during Cool-Down after Curing
Authors: Yi Sung , Chian Kerm Sin , Hilton Harry H.
Published: July 2003

Thermally induced stresses that occur during the cool-down process after curing are investigated on the basis of nonlinear thermo-viscoelastic finite element methods. Nonlinear viscoelastic stress singularities near free edges of laminated composites are evaluated as a function of time and cool-down history. Various cool-down histories are considered. Temperature distributions inside composites are predicted by solving heat conduction equations. Numerical results indicate a strong sensitivity to the nonlinearities of viscoelastic constitutive relations. Temperature history significantly affects residual interlaminar and in-plane stresses. The rate of stress relaxation also varies with the loading history.
The Response of Composite Joints with Bolt-Clamping Loads, Part I: Model Development
Authors: Sun Hsien-Tang , Chang Fu-Kuo , Qing Xinlin
Published: July 2003

A three-dimensional model was proposed to analyze the response of bolted composite joints with and without lateral clamping forces from initial loading to ultimate failure. The effects of the clamping force, bolt stiffness, washer size on the response and failure of the joints were the major concern of the study. The model consists of a progressive failure analysis and a finite element stress analysis. For a given stress state in a joint, the progressive failure analysis predicts damage accumulated in composites by a set of failure criteria and estimates associated material degradation based on predicted modes of failure. To account for threedimensional bearing damage in joints, the model assumed that the material suffering from bearing damage became incompressible under lateral bolt constraints provided by the washers. In the stress analysis, the commercial finite element code ABAQUS was adopted to provide three-dimensional stresses and strains which are needed for the progressive failure analysis. A 3-D composite brick element was used, and slip/friction/ contact conditions were applied between the elastic bolt and a composite plate, and between the composite plate and the elastic washers or side plates. In order to reinforce the incompressibility condition for bearing-damaged material, the condition was imposed through a penalty method in the framework of finite element analyses. The proposed model was implemented in a code, namely 3DBOLT, in order to interface with the ABAQUS code. The code provides a user-friendly input deck, automatically generates a joint mesh, and produces output and graphics for displaying the stresses, strains, and deformations of the joints and for simulating the failure progression in joints during loading.
The Response of Composite Joints with Bolt-Clamping Loads, Part II: Model Verification
Authors: Sun Hsien-Tang , Chang Fu-Kuo , Qing Xinlin
Published: July 2003

Extensive experiments were performed to characterize the material response due to bearing failure in composite bolted joints with and without lateral clamp-up supports. Composite plates made of T800H/3900-2graphite/epoxy were selected in the tests, and various washer sizes and clamping forces were used in the study. The clamping force in the bolt was found to vary with the applied load, and may increase significantly due to a sudden through-the-thickness expansion of the laminate under the washers where bearing failure occurred. Experiments showed that the joint strength and response can be significantly affected by the bolt clamp-up, and the bolt bearing failure is a 3-D phenomenon. The results of the tests were utilized to verify the model predictions proposed in Part I of the study. The model predicts both the failure load and response of bolted composite joints very well for various clamping forces and washer sizes. The predicted bolt clamp-up load as a function of the applied load agreed also well with the data, which validates that the proposed incompressibility assumption in the model for bearing-damaged material. Based on the model, a parametric study was performed to evaluate the sensitivities of bearing load to bolt stiffness, clamping force, washer size, joint geometry such as width, edge distance and bolt sizes.
Stress and Failure Analysis of 3D Angle Interlock Woven Composites
Authors: Naik N. K. , Azad Sk. N. M. , Prasad P. Durga
Published: July 2003

A three-dimensional woven composite strength model is presented for predicting the failure behavior of three-dimensional angle interlock woven composites under on-axis uniaxial static tensile loading and shear loading. The model is based on two-level discretization of the repeating unit cell. The repeating unit cell is discretized into sections, elements, subsections and subelements. The model predicts the stress levels at which the secondary failures take place at subelementlevel. The effectof secondary failure is considered for further analysis and the ultimate tensile strength and shear strength and the corresponding strains are predicted. A parametric study has been carried out for different 3D angle interlock woven composite configurations.
Effect of Surface Treatment on Mechanical Properties of Polyethylene Composite
Authors: Rochette A. , Bousmina M. , Lavoie A. , Ajji A.
Published: July 2003

A one-polymer composite made by PE/UHMPE fibers was previously studied; its thermal properties and the transcrystallization of the matrix over the fibers was observed. In this present study, the influence of surface treatment of the fibers of a one-polymer composite made of PE reinforced with UHMPE fibers, on the properties of the composites was studied. The fibers were first used with their initial sizing; then, they were used after either etching in chromic acid or plasma treatment of their surface. Stress–strain behavior in longitudinal and in transverse directions of the unidirectional composite and pull-out tests were performed. The crystallization of the matrix on the fiber surface was followed by microscopy and by DSC analysis. The structure of the interface was then observed by wide angle X-ray diffraction. Rheological experiments were conducted on the matrix and on the composites to evaluate the influence of the interface on dynamical properties at low frequencies.
Multilevel, Micro/Macro-Approach for Analysis of Woven-Fabric Composite Plates
Authors: Kwon Y. W. , Altekin A.
Published: July 2003

An approach wasdeveloped to analyze woven-fabric composite structures based on microlevel properties of the fiber and matrix materials. The approach is based on bilateral relationships among the fiber and matrix materials, unidirectional composites (strands), woven fabric layers, and laminated composite structures, as given in the sequence. Simplified analytical models were developed for the relationship between any two subsequent levels. The approach can predict the stiffness, strength and progressive failure of woven-fabric composite structures using material properties of the fiber and matrix materials, their volume fractions, and the information for weaving and lamination. Progressive failure can be described at the fundamental level like fiber failure, matrix failure and interface failure. Example problems were presented for evaluation of predicted stiffness, strength, and failure for plain-weave composite plates subjected to inplane or bending loads.
A Constitutive Model for Glass Fibre Fabric Composites under Impact
Authors: Dechaene R. , Degrieck J. , Iannucci L. , WILLOWS M.
Published: July 2003

A new composite constitutive failure model for woven glass fibre fabric reinforced with epoxy/polyester was developed, and implemented into an explicit dynamic non-linear finite element code for both the shell and solid element implementation. The approach uses a novel damage mechanics formulation to predict both matrix cracks and fibre fracture in the warp and weft directions with the woven fabric composite, subject to an impact or other dynamic event. Strain-rate effects are implicitly incorporated into the model using a damage lag methodology. Results are compared with laboratory composite beam and plate impact experiments. The comparisons indicate that the damage model can predict with reasonable accuracy the damage modes observed in the laboratory experiments. Conclusions are presented also on the logical extensions to the damage formulation necessary to improve both the accuracy and the scope of composite materials that may be analysed.
Evaluation of Fiber Orientation in Ferromagnetic Short-Fiber Reinforced Composites by Magnetic Anisotropy
Authors: Watanabe Yoshimi
Published: July 2003

Controlling preferentially oriented fibers in short-fiber reinforced composites is of great interest in determining various properties of the materials. This paper presents a new technique, the magnetic anisotropy measurement, which can effectively determine the fiber orientation in short-fiber reinforced composites. Theoretical magnetic torque curves are calculated for the composites with several different fiber distributions. The results are compared with those in prior work; the orientation descriptor obtained from the magnetic anisotropy measurement is mathematically equivalent to the well-known Hermans’ orientation parameter.
An Inelastic Damage Model for Fiber Reinforced Laminates
Authors: Barbero Ever J. , Lonetti Paolo
Published: July 2003

A new modelfor damage behavior of polymer matrix composite laminates is presented. The model is developed for an individual lamina, and then assembled to describe the nonlinear behavior of the laminate. The model predicts the inelastic effects as reduction of stiffness and increments of damage and unrecoverable deformation. The modelis defined using Continuous Damage Mechanics coupled with Classical Thermodynamic Theory. Unrecoverable deformations and Damage are coupled by the concept of effective stress. New expressions of damage and unrecoverable deformation domains are presented so that the number of model parameters is small. Furthermore, model parameters are obtained from existing test data for unidirectional laminae, supplemented by cyclic shear stress strain data. Comparison with lamina and laminate test data are presented to demonstrate the ability of the model to predict the observed behavior.
Masonry Strengthened with FRP Subjected to Combined Bending and Compression, Part II: Test Results and Model Predictions
Authors: Kiss Rita M. , Kollar Laszlo P. , Jai John , Krawinkler Helmut
Published: July 2003

This paper presents the results of experiments performed on masonry beams subjected to four-point bending. Four types of fiber-reinforced plastics (FRP) were used as reinforcement material: chopped glass fiber with epoxy resin,chopped glass fiber with polyester resin,glass fabric cloth with epoxy resin, and glass fabric cloth with polyester resin. In spite of the elastic-brittle behavior of FRPs,the experiments showed significant nonlinearity in load–deflection relationships due to the effect of delamination between the FRP and the masonry. In the second part of this article the behavior of masonry beams strengthened with FRPs is studied analytically. The effect of the reinforcement type (material,thickness, failure stress,and bond strength) on the failure load and ductility of a masonry beam is investigated.
Processing Induced Warpage of Filament Wound Composite Cylindrical Shells
Authors: Meink Troy E. , Huybrechts Steven , Shen M. -H. Herman
Published: July 2003

In this paper a systematic procedure is developed to eliminate the processing induced warpage in filament wound and fiber placed composite parts. This is accomplished by first developing a through-thickness strain model based on fiber/resin cure consolidation (also referred to as a compaction) and tooling thermal expansion. The lay-up or stacking sequence can be arbitrary (i.e., symmetric or asymmetric). The strain profile model is then integrated into classical laminate theory and solutions for predicting and eliminating warpage are obtained. The accuracy of both solutions is evaluated by comparison with experimental data. To facilitate this, cylindrical test specimens were manufactured and the cure consolidation and warpage measured. It was found that the predictions were accurate and the warpage could be reduced and eliminated in most cases. The majority of cure consolidation in composites results from resin bleed-out and evacuation of entrapped air (voids). The magnitude is dependent on manufacturing parameters including cure pressure, winding tension, and material characteristics (i.e., pre-preg fiber volume fraction, resin viscosity, etc.). The strain profile that develops is set once the resin cures and is therefore not a hygrothermal phenomenon and is independent of cure temperature, or finished part operational environment.