bluuebunny/crossref_metadata_2025 huggingface dataset:
Shock Parameters in a Two Component Mixture
Authors: Duvall G.E. , Taylor S.M.
Published: March 2007

A thermodynamically consistent procedure, based on the Gibbs free energy, is described for computing the thermodynamic properties of a mixture in equilibrium at constant pressure and temperature. This is used to compute temperatures, pressures, Gruneisen parameters and sound velocities on the Hugoniot for mixtures of polyethylene and quartz. The results show that a simple mass-weighted average for the Gruneisen parameter is inaccurate and that the mixture of two mate rials for which Γ/V = constant does not itself have a constant value of r/V. Some comments are made on problems of equilibrium of stress and temperature in composite materials.
Structure-Property Relations and Reliability Concepts
Authors: Halpin John C.
Published: March 2007

Typical procedures currently employed in engineering design are reviewed and applied to the evaluation of composite technology as it exists at this time. Special attention is directed to the topics of stiffness, static strength, specific weight, fatigue, structural reliability and adhesive joining. Verifica tion of the achievement of a safe composite design by a proof-test concept is introduced. Evaluation of composites vis-a-vis metallic technology yields a positive attitude toward the future of composite technology. Significant support is found to justify the long-term potential of advanced filamentary composites.
The Dynamic Fracture Toughness of Carbon-Carbon Composites
Authors: Hoover W.R. , Guess T.R.
Published: March 2007

The dynamic fracture toughness of two types of carbon-carbon com posites (filament wound and felt substrate) and ATJ-S graphite was deter mined from instrumented Charpy impact tests. The resistance to crack initiation from a pre-existing flaw (notch) was examined by investigating the dynamic fracture toughness, KD, a linear elastic fracture mechanics parameter. The resistance to crack initiation and propagation was deter mined using the dynamic work-of-fracture parameter, γ fD. Testing was conducted over a range of impact velocities (4.0-202.8 in/sec), and the parameters KD and γ fD were found to be strongly sensitive to impact velocity for all three materials. As expected, the dynamic fracture tough ness of the highly anisotropic filament wound carbon-carbon composite was dependent on filament orientation.
Stress Wave Propagation in a Cloth- Laminate Carbon Phenolic
Authors: Sutherland Herbert J. , Munson Darrell E.
Published: March 2007

The mechanical response of a cloth-laminate carbon phenolic, 2D-CP, to stress waves is examined. Acoustic water-bath experiments are used to obtain data about the propagation characteristics of low-amplitude waves, and plate-slap experiments are used to obtain data for finite-amplitude waves. From the data gathered in these experiments, a constitutive equa tion is derived for this material which is used to model its "thin-pulse- attenuation" characteristics. The results of the modeling illustrate that although this material is composed of high modulus fibers embedded in a low modulus matrix, it behaves for all intents and purposes as a homoge neous material.
Moisture Detection in Composites Using Nuclear Reaction Analysis
Authors: Deiasi Richard J. , Schulte Robert L.
Published: March 2007

An experimental method for evaluation of the localized moisture con tent in graphite epoxy composites or other organic solids is described. The method involves specimen conditioning in D2 O, followed by measurement of the localized deuterium concentration by means of the D ( 3 He, p)4 He nuclear reaction. Equilibrium moisture levels in two epoxy resins and two graphite epoxy composites measured by the nuclear technique are con sistent with those obtained from bulk gravimetric methods. Moisture pro files measured in a unidirectional graphite epoxy composite are compared to predictions from diffusion theory.
Initiation and Growth of Transverse Cracks and Edge Delamination in Composite Laminates Part 2. Experimental Correlation
Authors: Crossman F.W. , Warren W.J. , Wang A.S.D. , Law G.E.
Published: March 2007

In part one of this paper, the fracture processes of multiple transverse cracking and free edge delamination in composite laminates have been analyzed by an energy method. Numerical analyses and experimental examination using a series of T300/934 graphite epoxy laminates are pre sented in this part two. While part one is presented in a self-contained form, part two must be regarded as the continuation of part one.
Combustion Promotors for Safe Disposal of Carbon Fiber Reinforced Plastics
Authors: Reardon Joseph P. , Kaufman Samuel , Johnson Lee M.
Published: March 2007

Carbon filaments disseminated into the environment by combustion of carbon fiber/resin composites threaten electrical and electronic equipment, including power distribution and communications systems. The anticipated use of such composites in structural parts of aircraft, automobiles, and con sumer goods requires that the hazard be minimized in the inevitable events of flaming aircraft and auto crashes and other incinerations. The electrical hazard is mitigated by combustion promotors, and several substances have been evaluated in this role. The decreasing order of effectiveness among the species studied is PbO, Pb[OOC(CH2)8COO(C8H17)] 2, Pb3O4, Bi2O2CO 3,Bi2O3, Bi, CuO, CaCO3, Ca(OOCCH 3)2 H2O, Sb2O3. The lead compounds are not significantly separated in rank, and the ranking of CuO in the list is somewhat uncertain. Sb2O3 shows no activity as a combustion promotor.
Enchancement of Strength in Composites Reinforced with Previously Stressed Fibers
Authors: Manders Peter W. , Chou Tsu-Wei
Published: March 2007

Failure of a fiber in an aligned composite causes a stress wave to propagate outwards placing a dynamic overstress on the neighboring fibers. This is generally greater than the static stress concentration factor which prevails after the system has settled, and increases the probability that adjacent fibers also fail, weakening the composite. This analysis shows how weak fibers may be pre-fractured to eliminate the dynamic overstress, thereby increasing the strength of the composite. This strength enhancement is discussed with reference to the level of pre-stress, fiber variability, stress concentration factors, and size of the composite.
Fatigue Crack Propagation in Random Short-Fiber SMC Composite
Authors: Wang S.S. , Chim E.S.-M. , Zahlan N.M.
Published: March 2007

An investigation of the kinetics of fatigue crack growth in a random short-fiber rein forced SMC composite is presented. Experiments were conducted on notched SMC- R50 composite specimens subjected to cyclic uniaxial tensile and mixed-mode fatigue loading. Fatigue crack propagation rates were studied in terms of fracture mechanics parameters. A power-law relationship between the crack growth rate and the cyclic stress intensity factor range was obtained for the SMC-R50 composite under various fatigue loading modes. The value of the exponent in the power-law equation was found to be much higher for the composite than values reported for metals and some structural polymers. A fractographic study of fatigue fracture surfaces was also con ducted. Mechanisms of fatigue crack growth in the SMC-R50 composite were iden tified. A mechanical model is then proposed for further study of the mechanics of fatigue crack growth in random short-fiber SMC composites.
Arbitrarily Oriented Cracks in a Layered Media
Authors: Omoike G. , Vilmann C.R.
Published: March 2007

Cracks occurring at arbitrary orientations in lamellar composites are studied. The associated boundary value problem is formulated in terms of dual integral equations in which the kernels are found in series form. This series representation of the kernels is shown to converge quite rapidly. Variation of the stress intensity factors with the constituent elastic moduli is presented, and a comparison of calculated values with a Mohr's circle approximation of the stress intensity factors at arbitrary orientations is made. This comparison results in the conclusion that the Mohr's circle approximation is accurate as long as the crack tip is far enough from the bimaterial interface.
Thermoelastic Behavior of Thick Glass/Epoxy Composite Laminates
Authors: Raghava R.S. , Valentich J. , Nathenson R.D.
Published: March 2007

This paper compares the thermal properties of thick (2.125 ") versus thin (0.212 ") laminates of glass/epoxy composites. The influence of post-curing thick laminates on the hysteresis loop generated during heating-cooling cycles of linear coefficient of ther mal expansion (LCTE) measurement has been examined. Problems associated in the measurement of LCTE of thick laminates using dilatometry and strain gages are dis cussed.
Analysis of Progressive Matrix Cracking in Composite Laminates I. Thermoelastic Properties of a Ply with Cracks
Authors: Dvorak George J. , Laws Norman , Hejazi Mehdi
Published: March 2007

Overall stiffnesses and compliances, thermal expansion coefficients, and stress and strain averages are evaluated for a fibrous composite lamina which contains a given density of open transverse cracks and is subjected to uniform mechanical loads and thermal changes. The evaluation procedure is based on the self-consistent method and is similar, in principle, to that used in finding elastic constants of unidirectional com posites.
Role of Matrix Resin on Fracture Strengths of Unidirectional CFRP
Authors: Miyano Yasushi , Kanemitsu Manabu , Kunio Takeshi , Kuhn Howard A.
Published: March 2007

As a common feature of composite materials, prominent anisotropy in mechanical prop erties is observed in unidirectional CFRP, which has higher fracture strength and stiffness along the carbon fiber strengthening component. Since it is well known that a resin matrix exhibits characteristic time and temperature dependence on mechanical behavior, that is, viscoelastic behavior, the CFRP is expected to exhibit similar behavior.
Mechanical Properties of Some Silicon Carbide Reinforced Aluminum Composites
Authors: Tsangarakis Nikos , Andrews B.O. , Cavallaro C.
Published: March 2007

The mechanical properties of several particulate and continuous fiber silicon carbide reinforced aluminum composites were examined. The tensile strength of a 47 % silicon carbide fiber unidirectionally reinforced aluminum composite was 1,273 and 76 MPa par allel and normal to the fiber direction, respectively. The tensile strength of [0°/90°]4s and [0°2/90°/0°]s composites were 629 and 864 MPa, respectively. The tensile properties of a 30% silicon carbide particulate reinforced aluminum were found to depend on the chemistry of the metal matrix. The endurance limits of the fiber and the particulate rein forced aluminum were at the most 55 % and 33% of the respective tensile strengths. The fracture toughness of the fiber reinforced composite varied with specimen width, while that of the particulate reinforced composite was 21-29 MPa √m. The fatigue crack growth rate in the latter composite decreased with material thickness. There were indications that the fatigue crack growth rate in the silicon carbide particulate reinforced aluminum may be independent of variations in the chemistry of the metal matrix.
Impact-Induced Delamination—A View of Bending Stiffness Mismatching
Authors: Liu Dahsin
Published: March 2007

Fiber-reinforced composite materials are very susceptible to impact loading. The damage characteristics of a composite material subjected to subperforation impact can be classified as indentation, fiber breakage, matrix cracking, fiber-matrix debonding and delamination. Among these damage modes, delamination has been found to be important for all cases of loading. In this study, the damage characteristics of many composite plates made of glass/epoxy, Kevlar/epoxy, and graphite/epoxy were investigated. Delaminations in the impacted composite plates were inspected by high-intensity light, X-ray radiog raphy, ultrasonic imaging system and edge replication. It was found that delamination in every interface of impacted composite plates had a peanut-like shape. Since membrane ef fect could be ignored in this study, stresses caused by bending were the major stresses which should be responsible for the delamination. Although the interlaminar stresses had been analyzed by many investigators for the determination of delamination, in this study, however, the mismatching of bending stiffness between two adjacent laminae was pro posed as an indicator of delamination in the composite laminates subjected to subperfora tion impact. The effects of material properties, stacking sequence and thickness on the delamination were discussed. The justification of the hypothesis of bending stiffness mis matching was also presented.
A Statistical Theory of Composite Materials Strength
Authors: Yuntian Zhu  , Benlian Zhou  , Guanhu He  , Zongguang Zheng
Published: March 2007

A statistical tensile failure theory of composite materials with uniaxially oriented fibers is proposed. In the theory, the strength of fibers is assumed to be a statistical quantity and the fibers around a broken fiber are supposed to be subjected to localized stress concentra tions. The number of broken fibers in a layer of composite as a function of average tensile stress is derived first, and the strength of composite is derived consequently. Comparisons with previous works show better agreement with experimental data.
Prediction of Coefficients of Thermal Expansion for Unidirectional Composites
Authors: Bowles David E. , Tompkins Stephen S.
Published: March 2007

Several analyses for predicting the longitudinal, α1, and transverse, α2, coefficients of thermal expansion of unidirectional composites were compared with each other, and with experimental data on different graphite fiber reinforced resin, metal, and ceramic matrix composites. Analytical and numerical analyses that accurately accounted for Poisson re straining effects in the transverse direction were in consistently better agreement with ex perimental data for α2 than the less rigorous analyses. All of the analyses predicted similar values of α1, and were in good agreement with the experimental data. A sensitivity analysis was conducted to determine the relative influence of constituent properties on the predicted values of α1 and α2. As would be expected, the prediction of α1 was most sensi tive to longitudinal fiber properties and the prediction of α2 was most sensitive to matrix properties.
Moisture Absorption and Fracture Toughness of PEEK Polymer and Graphite Fiber Reinforced PEEK
Authors: Qiuling Wang  , Springer George S.
Published: March 2007

Tests were conducted to determine the moisture absorption characteristics of PEEK 150P polymer and APC-2 composite exposed to humid air, and to evaluate the effects of moisture content and crystallinity on the fracture toughness. Tests were con ducted with PEEK 150P specimens having 30, 34, and 43 percent crystallinities and with APC-2 specimens having 17 and 21 percent crystallinities. The weight gains of these speci mens were measured during exposure to air kept at relative humidities ranging from 60 to 100 percent and temperatures ranging from 140 to 200°F. The values of the maximum moisture content and diffusivity were deduced from the weight gain data. Empirical cor relations were established for the maximum moisture content and for the diffusivity. The room temperature fracture toughnesses of PEEK 150P and APC-2 were measured. For the conditions of the tests the fracture toughness was found to be unaffected by crystallinity and by moisture content.
Mode II Interlaminar Fracture of the Center Notch Flexural Specimen under Impact Loading
Authors: Maikuma Hironori , Gillespie John W. , Wilkins Dick J.
Published: March 2007

The Mode II interlaminar fracture of unidirectional graphite/epoxy (AS4/2220-3) and graphite/polyetheretherketone (APC-2) composite laminates subjected to impact loading is investigated using the Center Notch Flexural (CNF) test specimen. Experimentally, instrumented impact testing of the CNF specimen enables the impact force history and the absorbed energy during delamination propagation to be estimated. Scanning electron microscopic examination is conducted to assess the influence of impact loading on fracture morphology in the crack initiation and propagation regions of the frac ture surface. Data reduction for evaluating the Mode II interlaminar initiation toughness is based upon beam theory that includes kinetic energy effects and dynamic finite element analysis of the specimen in conjunction with virtual crack closure techniques. The initia tion toughness under impact loading was approximately 20 and 28% lower than the static values for AS4/2220-3 and APC-2, respectively. Data reduction for evaluating the Mode II interlaminar propagation toughness is based upon the area method and a 24 and 44% reduction in fracture toughness is measured for the AS4/2220-3 and APC-2 composite materials, respectively.
On Sandwich Beams with Laminate Facings and Honeycomb Cores Subjected to Hygrothermal Loads: Part II-Application
Authors: Mukhopadhyay A.K. , Sierakowski R.L.
Published: March 2007

The general results for the sandwich beam with laminate facings and honey comb core obtained in Part I are applied to specific problems in this paper. As an example, a simply supported beam under a uniformly distributed load is considered. In addition to a mechanical load, the beam is subjected to hygrothermal loads as well. The behavior of various stiffness coefficients, pertinent parameters, and the distribution of stresses across the laminate facings for varying core thickness and facing orientations are presented graphically.
A Stiffness Degradation Model for Graphite/Epoxy Laminates
Authors: Yang J.N. , Jones D.L. , Yang S.H. , Meskini A.
Published: March 2007

Stiffness reduction in composite laminates is an important measure of fa tigue damage. The determination of fatigue damage and the prediction of fatigue life can be made through the development of a stiffness degradation model. This paper proposes a stiffness degradation model that can be used to predict the statistical distribution of the residual stiffness of composite laminates subjected to fatigue cycling. Based on the pro posed model, two analytical methods are presented, which are capable of predicting the stiffness degradation of a particular composite specimen under cyclic loading. One method is based on the linear regression analysis and the other on the Bayesian approach. Experi ments have been performed on graphite/epoxy [90, +45, —45,0], laminates to generate sta tistically significant data for evaluating the proposed analytical models and for verifying the predicted results. It is shown that theoretical predictions for the stiffness degradation of an individual specimen and for the statistical distribution of the entire population corre late reasonably well with experimental results.
Crushing Characteristics of Continuous Fiber-Reinforced Composite Tubes
Authors: Farley Gary L. , Jones Robert M.
Published: March 2007

Composite tubes can be reinforced with continuous fibers. When such tubes are subjected to crushing loads, the response is complex and depends on interaction between the different mechanisms that control the crushing process. The modes of crush ing and their controlling mechanisms are described. Also, the resulting crushing process and its efficiency are addressed.
Fiber-Matrix Adhesion and Its Effect on Composite Mechanical Properties. III. Longitudinal (0°) Compressive Properties of Graphite/Epoxy Composites
Authors: Madhukar Madhu S. , Drzal Lawrence T.
Published: March 2007

An experimental investigation was performed to quantify the relationship between fiber-matrix adhesion as determined by single fiber interfacial shear strength tests with the compressive properties and failure modes of unidirectional graphite/epoxy com posites. The compression tests were conducted on three identical sets of composites differ ing only in their fiber-matrix interfacial shear strength. The interfacial shear strength was varied by using the same graphite fibers with different surface treatments, namely un treated, surface treated, and surface treated and coated with a thin layer of epoxy. The sur face treatment changed the interfacial shear strength by more than a factor of two, while the properties of the fibers remained unchanged. The experimental results show that the fiber surface treatment affects the compressive modulus only marginally. However, the compressive strength and maximum compressive strain were highly sensitive to the fiber surface treatment. Both the strength and maximum strain increased with the interfacial shear strength. The fracture surface analysis revealed that when the fiber-matrix inter facial shear strength was low the compressive failure occurred due to delamination and global delamination buckling. At intermediate values of the interfacial shear strength, the compressive failure occurred due to shear failure driven by inphase microbuckling of fibers. The composites having the highest values of the interfacial shear strength yielded "stepped" fracture surfaces showing compressive failure of fibers in several planes perpen dicular to the fiber axis.
The Effect of Side Loads on the Energy Absorption of Composite Structures
Authors: Fleming David C. , Vizzini Anthony J.
Published: March 2007

Slightly tapered truncated cones were manufactured from graphite/epoxy preimpregnated unidirectional tape and were loaded in compression. Different amounts of side loads were introduced by orienting the loading axis away from the central axis of the cone. The cones were crushed under quasi-static conditions, and their energy absorption was measured. For small amounts of side load, the energy absorbency was improved; however, as the amount of side load is increased further, the energy absorption capability of the structure is reduced significantly. Furthermore, a tendency for the specimen to topple is observed as a result of the moment induced by the side loads which reduces the energy absorption properties even further.
The 3-D Deformation Behavior of a Lubricated Fiber Bundle
Authors: Cai Z. , Gutowski T.
Published: March 2007

The purpose of this paper is to describe the response of an aligned, lubri cated fiber bundle to a general state of three-dimensional stress. Such an element can be used to represent an advanced composite during manufacturing. In general, this bundle can deform by both viscous shearing, and by "cylindrical" modes of elastic dilation. For a transversely isotropic bundle we show that there are five material functions needed to describe the constitutive behavior of the bundle, namely; 2 viscous functions, and 3 elastic functions. We first outline the viscous responses, and then derive functional relationships and compliances to describe the elastic behavior of the bundle. The application of this model to practical problems such as filament winding, prepregging, consolidation and fiber waviness are discussed.
Material Improvement and Quality Assurance for Composite Leaf Springs Based on Microfracture Mechanism
Authors: Sato Norio , Kurauchi Toshio , Kamigaito Osami
Published: March 2007

The understanding of the microfracture mechanism is essential for the im provement of the performance of the materials and the establishment of the quality assurance procedures. In this study, the microfracture mechanism of composite leaf springs produced from unidirectional glass fiber reinforced epoxy resin was studied using acoustic emission technique in combination with in situ failure analysis using SEM. It was found that the fracture mechanism consists of the following two steps: the breakage of in dividual fibers followed by matrix microcracking from the broken fiber tips, and the simultaneous breakage of some tens of fibers accompanied by small delamination failure from the broken tip, leading to final failure. It was found that the mechanical property of the matrix was greatly improved by modifying the epoxy resin, which results in a retarda tion of matrix microcracking from the broken fiber tips. This retardation, confirmed by the acoustic emission measurement and in situ failure analysis, can greatly improve the dura bility of the material. The microfracture mechanism of a prototype composite spring was characterized under flexural loading using the acoustic emission measurement. Based on the result, an optimum geometrical design of the spring to reduce the microfailure was ob tained. During this study, the employment of the acoustic emission technique as a quality assurance test of the spring was assessed. It was found that improperly manufactured springs generate a lot of the emission by loading to a maximum design load, while prop erly manufactured ones hardly generate the emission. It can be concluded that the acoustic emission technique is effective as a quality assurance test for the composite springs.
Impregnation Dynamics of Carbon Fiber Tows
Authors: Bayramli Erdal , Powell Robert L.
Published: March 2007

Axial and normal (transverse) impregnation of fiber bundles are in vestigated. A slow curing epoxy system is used with the impregnation being driven solely by capillary forces. Axial impregnation rates are found to be faster than expected based on Lucas-Washburn type capillary wicking. For normal mode impregnation, geometric limi tations and the dependency of contact angles upon wetting speed give rise to rates which are an order of magnitude slower than axial wetting. Transverse impregnation is also strongly influenced by pores much smaller than the overall average porosity of fiber bun dles. These results indicate that incomplete wetting and void formation may result from: (1) (dynamic) contact angles larger than 45°, and (2) large differences in the rates of axial and normal impregnation.
A Parametric Study of Variables That Affect Fiber Microbuckling Initiation in Composite Laminates: Part 2 — Experiments
Authors: Guynn E. Gail , Bradley Walter L. , Ochoa Ozden O.
Published: March 2007

The objectives of this research are to investigate the effects of stacking se quence (orientation of plies adjacent to the 0° plies), free surfaces, fiber/matrix interfacial bond strength, initial fiber waviness, resin-rich regions, and nonlinear resin shear consti tutive behavior on fiber microbuckling initiation. Three thermoplastic composite material systems are used in this investigation. The materials are the commercial APC-2 (AS4/ PEEK), QUADRAX Interlaced Tape, and a poor interface experimental material, AU4U/ PEEK. Notched compression specimens are studied at 21°C, 77 ° C, and 132°C. Observa tions indicate that the notch radius controlled fiber microbuckling initiation, and thus compression strength, by dictating the unsupported fiber length at the notch. The numeri cal results from a companion paper [1] are compared qualitatively with these experimental results. The results show that increasing the test temperature, locating 0° plies at the free surface of the laminate, and degrading the fiber/matrix interfacial bond strength reduce the resistance to fiber microbuckling initiation in these notched laminates. The fiber micro buckling initiation strain is shown to be a constant, regardless of stacking sequence, for these notched laminates. Experimental results show that resin-rich regions also reduced the resistance to fiber microbuckling initiation.
Solid Particle Erosion of Fiber Reinforced Plastics
Authors: Miyazaki N. , Takeda N.
Published: March 2007

Solid particle erosion tests were carried out to study the effect of matrix materials, reinforcement fibers, interface strength between matrix material and fibers, im pact angle, and particle velocity on the solid particle erosion behavior of fiber reinforced plastics. In the present study, special attention was focused on the effect of the interface strength between matrix material and fibers, which has not been investigated in a lot of previous works related with the erosion of composite materials. FRPs with treated or un treated fiber surfaces were used as test materials to study the effect of interface strength be tween matrix material and fibers. It is found from the erosion tests that the erosion rate is larger in a FRP than in a neat resin, and that the erosion rate of a FRP decreases with the increase of the interface strength between matrix material and fibers.
The Effect of Cooling Rate and Annealing on Residual Stress Development in Graphite Fibre Reinforced PEEK Laminates
Authors: Unger W.J. , Hansen J.S.
Published: March 2007

The effect of cooling rate from the molten state and annealing from the amorphous state on thermal and crystallization residual stress development in graphite fibre reinforced polyetheretherketone (APC-2) laminates is studied experimentally by measuring the radius of curvature developed in (0/90) unsymmetric laminates. Curvature is measured for cooling rates ranging from 1.5°C/min to 8000°C/min, and for annealing temperatures ranging from 175°C to 250°C. Stress relaxation effects are also quantified.
Prediction of Delamination in Composite Laminates Subjected to Low Velocity Impact
Authors: Jih C.J. , Sun C.T.
Published: March 2007

A method for predicting impact-induced delamination in composite lami nates was proposed. This method is suitable for low velocity impact with heavy impactors. Static delamination fracture toughness was used to predict delamination crack growth under impact conditions. Curing stresses were also considered and found to play a signifi cant role in evaluating the fracture toughness of some laminates such as [905/05/90 5]. Ex periments were performed to obtain the impact force history from which the peak force was used to determine the extent of delamination crack length. The prediction of delami nation size using static fracture toughness was found to agree very well with the experi mental result.
Response of Composite Laminates to Contact Loads and Relationship to Low-Velocity Impact
Authors: Wu Enboa , Shyu Kae
Published: March 2007

Experimental results are presented for contact and low-velocity-impact re sponses of composite laminates by rigid spheres. The contact phenomenon is different in small and large indentation stages, which is due to occurrence of laminate damage. The contact force corresponding to the onset of laminate damage is found to be independent of the indentor size. In the small indentation stage where the plate is intact, the change of laminate stacking sequence has an insignificant effect on the force-indentation relation ship. However, the force-indentor size relationship does not follow the modified contact law for thin laminates indented by large indentors. Beyond the small indentation stage, damage occurs. The size of the delamination area is proportional to the applied loads and the number of repeated loading cycles. The passage of the delamination crack front can be detected using strain gauges. Also, the indentation spring becomes stiffer under repeated loading. Finally, the delamination damage and the strain history in a laminate at low- velocity impact are found to be very similar to those in the contact test except that vibra tion was observed in the impact test.
Attributes of Intelligent Behavior
Authors: Chen May Jane , Braithwaite Valerie , Huang Jong Tsun
Published: March 2007

The cross-cultural generalizability of two Western intelligence tests, the Stanford-Binet and the WAIS, in a non-Western culture was examined. Samples of 976 Australian and 1003 Chinese university and high school students participated in a rating task. Items from the two tests were given to students, and were rated on the two aspects of relevance and difficulty. On relevance ratings, the underlying three-factor structure of the Chinese sample accords very well with that of the Australian, suggesting a basic common structure for the concept of intelligence across cultures. The three factors were spatial-mechanical, verbal and memory. The results also showed that both cultures consider spatial-mechanical items most important and memory items least important. The two samples differed, however, in mean difficulty scores on the three dimensions. These differences were attributed to possible cultural differences in nurturing and providing opportunities to practice the different skills. It is concluded that the concept of intelligence is comparable between Australian and Chinese cultures, and that, for both cultures, the two tests are legitimate measures of the intelligence construct.
Linking Person Perception Dimensions to Behavioral Intention Dimensions
Authors: Bond Michael H.
Published: March 2007

Using Norman's (1963) procedures and materials, four independent dimensions of person perception (extroversion, good-naturedness, conscientiousness, and emotional stability) have been isolated in a number of different cultures. In addition, Triandis (1977) has identified four universal dimensions of interpersonal behavior: overtness, association, subordination, and formality. To explore the connection between these domains, 256 male subjects read about a same-sex peer whose description varied across the four dimensions of person perception. Half of the subjects anticipated the possibility of meeting this target person (TP). Subjects then indicated their behavior intentions toward the TP. As predicted, the behavioral factors of association, subordination, and formality were most highly influenced by variations across the perceptual dimensions of good-naturedness, conscientiousness, and emotional stability, respectively. Results also indicated the extensive influence of the good-naturedness variable and the unimportance of possible future interaction in this judgment task. The universality and cultural specificity of these results are discussed.
College Students' Spontaneous Self-Concept
Authors: Bond Michael H. , Cheung Tak-Sing
Published: March 2007

Cross-cultural comparisons of the self-concept have typically used structured inventories created in the United States. Importing and using such methodology may prevent culturally unique dimensions and contents from appearing. To overcome this problem, the Twenty Statements Test was administered to university students in Japan, the United States, and Hong Kong to assess cultural influences on the self-concept assessed from this open-ended inventory. Numerous cultural differences were found in the frequency of categories and subcategories used for self-statements and in the level of self-esteem. These differences were related to previous research on the self-concept, to socialization practices, and to central concerns in these cultural groups.
The Stigmatizing Effect of Facial Disfigurement
Authors: Bull Ray , David Idi
Published: March 2007

Most research on the stigmatizing effect of facial disfigurement has taken place in London, England. The present study found that irrespective of whether they were nurses or office workers, women both in Nigeria and in England rated faces that had a minor scar as less sociable, less attractive, and more dishonest than did women who saw the same stimulus faces when "normal." Few interactions were found between the variables of disfigurement, race of face, race of rater, and type of rater employment.
Arms Export Controls and Proliferation
Authors: Levine Paul , Smith Ron
Published: March 2007

Given that there are a relatively small number of suppliers of major weapons systems, control fo arms exports is possible, and there are a variety of regulatory regimes striving to achieve this. Controls can stabilize regional arms races and reduce tensions. However, when buyers can develop the capability to produce conventional or unconventional weapons, arms export controls can increase the incentive for proliferation. The authors discuss a general framework for analyzing the arms trade and examine the dynamic decision problem faced by a country deciding whether to make an irreversible investment in arms production capability under conditions of uncertainty.
Prejudiced Liberals?
Authors: Baxter George W.
Published: March 2007

Ninety white female freshmen very much in favor of integration played a Prisoner's Dilemma game in which information about the cooperativeness or competitiveness of the other player (significant, p <.04), the race of other player (p < .09), the native region of the United States of the subject (nonsignificant), and experience over three trial blocks of ten trials each (nonsignificant) were manipu lated. Subanalyses in the cooperative information condition showed cooperation was significantly less with the Negro other player than it was with the white other player (p <.02). Attitude and personality measures did not correlate significantly with total cooperation in the game, but high cooperators had low anxiety scores. The Negro other player was rated consistently lower than the white other player, especially on sociometric and ability traits. Further analyses of attitude and personality measures, ratings, and submeasures of cooperation showed the subjects were reacting differently to the Negro and white other players; consequently, an unexpected high rate of cooperation with the competitively described Negro other player, which resulted in a weak main effect for race, was itself interpreted as evidence of prejudiced behavior.
Cost and Dependency as Determinants of Helping and Exploitation
Authors: Gruder Charles L.
Published: March 2007

An experiment in a naturalistic setting investigated the effects of the cost of helping and the dependency and need of a recipient on whether she was helped or exploited. There were 2 levels each (high and low) of cost, dependency, and need. Forty-eight male subjects, 24 at each level of cost, interacted with each of four female experimental confederates who represented different combinations of levels of dependency and need. Subjects role-played a job applicant, and each dyad bargained over an hourly wage agreement. The extent to which the subject helped or exploited the confederate was defined as correlated with the wage at which he agreed to be hired: the higher his wage, the less the help or the greater the exploitation. The primary result, as in Schaps' (1972) study, was a cost by dependency interaction. However, while Schaps' interaction was primarily due to greater help given to the highly dependent other under low cost, the present interaction was primarily due to greater exploitation of the highly dependent other under high cost. Possible reasons for this divergence are discussed.
Trivial Games as Predictors of a Mixed-Motive Game
Authors: Katz Marsha
Published: March 2007

In the present study, two trivial games, one relevant to the trait of trust, the other to the trait of competition, were used to predict behavior in the mixed-motive game of Chicken. The results showed that behavior in the Chicken game was related to choice in the "competition" game but not in the "trust" game. Thus, findings suggested that competition is the dominant motive in the Chicken game, and they demonstrated the utility of using trivial games to determine the relative influence of the various motives that could be salient in mixed-motive situations.
The Effects of Game Structure and S's Behavior on Attitudes Toward Cooperative Opponents
Authors: Swingle Paul G.
Published: March 2007

Two experiments examined the effects of game structure and S's behavior on attitudes to opponents (O). Highly cooperative Ss, involved in either the PD, the power game, or the Chicken game, against a conditionally cooperative O, rated powerful Os as having more suspicious motives and less ability as compared to Os in the other games. Os in the Chicken game were rated least attractive. In the second study, a relationship was found between weak Ss' level of exploitation and the rating of the powerful Os' ability.
An Application of a Richardson Process Model
Authors: Hopmann P. Terrence , Smith Theresa C.
Published: March 2007

Richardson models have often been used to describe reactive processes in arms races. This paper argues that, following the work of Otomar Bartos, negotiations may also be analyzed as a reactive process rather than as a process of discrete position changes. Four variants of the basic Richardson model were employed to determine whether the Partial Test Ban negotiations exhibited such an interactive pattern. In all four equations for the behavior of both the United States and the USSR the stimulus variable provided the greatest explanatory power, supporting the notion that these negotiations were reactive. Several important differences emerged, however, between the Test Ban negotiations and most arms races. On balance, the data gave strong support for the basic assumption of Richardson models, namely that negotiations may be treated as a highly reactive process.
The Effects of Perceived Ability and Impartiality of Mediators and Time Pressure on Negotiation
Authors: Brookmire David A. , Sistrunk Frank
Published: March 2007

This study provided empirical clarification of the effects of factors presumed in the negotiation literature, but not clearly demonstrated, to be central to the negotiation process. One hundred and forty subjects participated in a simulated labor-management negotiation to determine the effects of perceived ability and impartiality of a mediator and time pressure on negotiation. Results showed that negotiators utilizing a mediator perceived to be high in ability gained more money, were influenced to a greater extent, and perceived the mediator as more powerful and favorable than negotiators with a mediator perceived to be low in ability. Also, negotiators bargaining with a high perceived-ability mediator ended with more money, were more influenced, and indicated more satisfaction than controls. Finally, time pressure produced more contract settlements in the high time-pressure situation than in the low time-pressure situation.
Terrorism as a Desperate Game
Authors: Corsi Jerome R.
Published: March 2007

This article examines terrorism both theoretically and empirically. A typology is presented to identify different types of terrorist events and characteristics particular to each. Following this, the negotiations involved in hostage situations are examined with emphasis on government / terrorist response options and event outcomes. Throughout the article, assumptions of the theoretical model are empirically tested utilizing the ITERATE data set. Decision routes are mapped as a method for conceptualizing the tactics involved in bargaining communications. Formal game theory is utilized to explore the complexities involved in modeling government/terrorist interaction regarding: (a) developing an extensive game form; (b) specifying utilities; and (c) constructing illustrative games. Probability functions for an empirically-based decision model are generated by an examination of government/ terrorist responses and outcomes for the cases in the data set. Discriminant function analysis is employed to specify quantitatively the degree to which theoretically identified types are distinct as posited. The argument presented emphasizes the significance of the communications (implicit and direct, calculated and manipulative) which result from the terrorist/target bargaining interaction.
The Political Consequences of Economic Dependence
Authors: Armstrong Adrienne
Published: March 2007

This analysis attempts to examine the ability of one nation to induce other nations to follow lines of policy which they might otherwise not pursue, as a result of their economic dependence on the former. To explore this relationship between economic dependence and political compliance, this study focuses on U.S. and Soviet economic exchanges with 24 nations as they relate to estimates of compliance. Moreover, this study develops a model for examining the relationship between dependence and compliance for differing categories of issues in order to determine under what situations economic dependence will be most successful in influencing political compliance.
Position Loss and Image Loss in Bargaining
Authors: Hiltrop Jean M. , Rubin Jeffrey Z.
Published: March 2007

Bargaining theorists have had a long-standing interest in understanding the relationship between the tangible and intangible aspects of concession-making—what Pruitt (1971) has described as the risks of "position loss" and "image loss," respectively. In order to evaluate the precise relationship between position loss and image loss, two questionnaire studies were conducted. In Experiment I, bargainers read a cover story describing a dyadic bar gaining episode and were asked to take the role of one of the disputants; they were then to rate the "image" associated with each of a series of offers, and the monetary concession values associated with a set of possible bargainer appearances in a within-subjects design. Experiment II was identical to the first study in all respects, except that only one offer and one bargaining appearance were rated in a between-subjects design. Subjects were found to discriminate better among various bargainer appearances in Experiment I than in Experiment II. In addition, an exponential relationship was found between image loss and position loss in Experiment I, while an ogive was obtained in Experiment II. Implications of the points of similarity and divergence in the results of the two studies are discussed.
Static Indicators and the Ranking of Strategic Forces
Authors: Richelson Jeffrey T.
Published: March 2007

Static (or preattack) indicators of the strategic balance attempt to summarize, via a single number or index, the capability of a nation's strategic nuclear arsenal prior to any conflict. This article illustrates the extent to which selection of an index allows one to determine the evaluation of alternative strategic arsenals.
Movements of “Crisis” and Movements of “Affluence”
Authors: Kerbo Harold R.
Published: March 2007

In response to the empirical and theoretical weaknesses of the older social stress or deprivation theories of social movements, a new general theory of social movements—resource mobilization theory—has become increasingly popular. One of the most basic points of disagreement between theorists accepting one or the other general perspective involves the extent to which the development and growth of a social movement can be attributed to the preconditions of social stress or some form of deprivation. This article begins by describing how the two perspectives are indirectly rooted in differeing paradigms of social organization, which leads to divergent assumptions about the nature of social conflict and social order. Next, theoretical and empirical problems contained in each perspective are shown to be partially related to these assumptions. Finally, a continuum describing “movements of crisis” and “movements of affluence” is constructed to suggest that the structural conditions inviting social movement activity are varied. When such variance is recognized, we find there is a place for both theories in the complex field of study, though deprivation theories especially face many continuing problems.
Rational Models and the Ending of Wars
Authors: Mitchell C. R. , Nicholson Michael
Published: March 2007

The article considers the problem of using the expected utility approach to war termination. In the context of the ending of the Boer War, the authors attempt to explain why an expected utility approach has difficulty in accommodating the fact that there was a long delay between the initiation of certain proposals for termination and the eventual acceptance of essentially the same terms. They conclude that the problem in this case was that neither of the decision maker was unitary, and that the process of formulating a preference ordering takes time. It is of course reasonable in a static theory to ignore this. However, to apply the process of decision-making as distinct for just the end result, we need a theory of the process of preference formulation in groups.