Mechanics of Composite Materials and Structures最新文献_第2页

Static and Dynamic Energy-Absorption Capacity of Graphite-Epoxy Tubular Specimens 石墨-环氧管状试件静、动态吸能性能研究

Mechanics of Composite Materials and Structures Pub Date : 2001-07-01 DOI: 10.1080/10759410121528

Marc R. Schultz, Michael W. Hyer, Hannes P. Fuchs

{"title":"Static and Dynamic Energy-Absorption Capacity of Graphite-Epoxy Tubular Specimens","authors":"Marc R. Schultz, Michael W. Hyer, Hannes P. Fuchs","doi":"10.1080/10759410121528","DOIUrl":"https://doi.org/10.1080/10759410121528","url":null,"abstract":"This article examines the energy-absorption capacity of 50k and 12k carbon fiber composite tubular specimens crushed axially, in both quasi-static and dynamic fashions. Round and square tubular specimens with - 45° and - 45°/0° fiber orientation schemes were studied. The fundamental issue was to compare the energy-absorption capacity of the lower-cost 50k material with the 12k material, and to examine the influence of specimen geometry, fiber orientation schemes, and dynamic effects on the energyabsorption characteristics. Specimens made from the 50k material absorbed less energy than similar specimens made with the 12k material, and the load ratios were generally higher for the 50k specimens. The square specimens tended to have lower values of specific energy absorption (SEA) than the circular specimens. In addition, the crush modes were somewhat different and the load ratios were generally higher for the square specimens than for the circular specimens. Changing the fiber orientation schemes did not have much of an effect on the SEA, nor on the crush modes, but the presence of 0° fibers led to higher load ratios for the 50k specimens. The specimens tested dynamically had lower SEAs and higher load ratios than similar specimens that were tested statically.","PeriodicalId":111254,"journal":{"name":"Mechanics of Composite Materials and Structures","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129560996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 12

Transverse Stress Decay in a Specially Orthotropic Strip under Localized Normal Edge Loading 局部法向边缘载荷作用下特殊正交异性带材的横向应力衰减

Mechanics of Composite Materials and Structures Pub Date : 2001-04-01 DOI: 10.1080/10759410120544

W. Fichter

{"title":"Transverse Stress Decay in a Specially Orthotropic Strip under Localized Normal Edge Loading","authors":"W. Fichter","doi":"10.1080/10759410120544","DOIUrl":"https://doi.org/10.1080/10759410120544","url":null,"abstract":"Solutions are presented for the stresses in a specially orthotropic infinite strip which is subjected to localized uniform normal loading on one edge while the other edge is either restrained against normal displacement only, or completely fixed. The solutions are used to investigate the diffusion of load into the strip and in particular the decay of normal stress across the width of the strip. For orthotropic strips representative of a broad range of balanced and symmetric angle-ply composite laminates, minimum strip widths are found that ensure at least 90% decay of the normal stress across the strip. In addition, in a few cases where, on the fixed edge the peak shear stress exceeds the normal stress in magnitude, minimum strip widths that ensure 90% decay of both stresses are found. To help in putting these results into perspective, and to illustrate the influence of material properties on load diffusion in orthotropic materials, closed-form solutions for the stresses in similarly loaded orthotropic half-planes are obtained. These solutions are used to generate illustrative stress contour plots for several representative laminates. Among the laminates, those composed of intermediate-angle plies, i.e., from about 30° to 60°, exhibit marked changes in normal stress contour shape with stress level. The stress contours are also used to find 90% decay distances in the half-planes. In all cases, the minimum strip widths for 90% decay of the normal stress exceed the 90% decay distances in the corresponding half-planes, in amounts ranging from only a few percent to about 50% of the half-plane decay distances. The 90% decay distances depend on both material properties and the boundary conditions on the supported edge.","PeriodicalId":111254,"journal":{"name":"Mechanics of Composite Materials and Structures","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114915183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparison of Creep Behavior of UD and Woven CFRP in Bending 碳纤维布与编织碳纤维布弯曲蠕变性能比较

Mechanics of Composite Materials and Structures Pub Date : 2001-04-01 DOI: 10.1080/10759410118348

Rui Miranda Guedes, MÁrio A. Vaz

引用次数: 9

Vibration Analysis of Arbitrarily Shaped Sandwich Plates via Ritz Method 任意形状夹层板的Ritz法振动分析

Mechanics of Composite Materials and Structures Pub Date : 2001-04-01 DOI: 10.1080/10759410117566

C. M. Wang, K. K. Ang, L. Yang, E. Watanabe

{"title":"Vibration Analysis of Arbitrarily Shaped Sandwich Plates via Ritz Method","authors":"C. M. Wang, K. K. Ang, L. Yang, E. Watanabe","doi":"10.1080/10759410117566","DOIUrl":"https://doi.org/10.1080/10759410117566","url":null,"abstract":"This article presents the Ritz method for the vibration analysis of sandwich plates having an orthotropic core and laminated facings. The planform of the plate may take on any arbitrary shape. On the basis of the Mindlin plate theory and the Ritz method, the governing eigenvalue equation for determining the natural frequencies was derived. The Ritz method was automated and made computationally effective for general-shaped plates with any boundary conditions by (1) adopting the product of polynomial functions and boundary equations that were raised to appropriate powers and (2) applying Green's theorem to transform the integration over the general-shaped domain into a closed line integration. The Ritz formulation and software were verified by the close agreement with vibration frequencies obtained by previous researchers for a wide range of subset plate problems involving isotropic, laminated, and sandwich plates of various shapes. Moreover, sample natural frequencies of sandwich plates with laminated facings are presented for some quadrilateral plate shapes. These frequencies should be useful as reference results to researchers who are developing new methods or software for vibration analysis of sandwich plates.","PeriodicalId":111254,"journal":{"name":"Mechanics of Composite Materials and Structures","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114774399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10

Micromechanical Bilinear Behavior of Composite Lamina Subjected to Combined Thermal and Mechanical Loadings 复合材料板在热和机械复合载荷下的微力学双线性行为

Mechanics of Composite Materials and Structures Pub Date : 2001-04-01 DOI: 10.1080/10759410119637

Heung Soap Choi, J. D. Achenbach, Cheol Kim

{"title":"Micromechanical Bilinear Behavior of Composite Lamina Subjected to Combined Thermal and Mechanical Loadings","authors":"Heung Soap Choi, J. D. Achenbach, Cheol Kim","doi":"10.1080/10759410119637","DOIUrl":"https://doi.org/10.1080/10759410119637","url":null,"abstract":"The bilinear elastic degradation called the \"knee\" phenomenon, observed well in the transverse tensile stress–strain curves of some metal-based composites, is modeled through both a simplified three-phase cylindrical model and a hexagonal-arrayed unidirectional composite. The interphase is modeled by spring layers which account for continuity of tractions, but allow radial and circumferential displacement jumps across the interphase that are linearly related to the normal and tangential tractions. Even though constituent materials are in the elastic range all the way through, the possible low stiffness of the interphase and the residual stresses induced by uniform cooling yield bilinear elastic behavior in the stress–effective strain curves. However, perfect bonding or low stiffness in the interphase with no residual stresses creates a linear curve. The effects of interphase stiffness, fiber volume fraction, temperature change, and transverse tensile load on both the micro- and macro-thermomechanical behaviors of unidirectionally fiber-reinforced composites are analyzed numerically using the boundary-element method. These results are then compared to the elastic solutions of the three-phase model in a qualitative manner.","PeriodicalId":111254,"journal":{"name":"Mechanics of Composite Materials and Structures","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124900614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Uniformly Valid Multiple Spatial-Temporal Scale Modeling for Wave Propagation in Heterogeneous Media 波在非均质介质中传播的均匀有效多时空尺度模拟

Mechanics of Composite Materials and Structures Pub Date : 2001-04-01 DOI: 10.1080/10759410121205

Jacob Fish, Wen Chen

引用次数: 30

Unusual Characteristics of Mixed-Mode Delamination Fracture in the Presence of Large-Scale Bridging 大规模桥接存在下混合模式分层断裂的异常特征

Mechanics of Composite Materials and Structures Pub Date : 2001-01-01 DOI: 10.1080/10759410120212

R. Cox

引用次数: 49

Mechanical Defects Deriving from the Manufacturing Process of High-Density Electronic Boards: Experimental Analysis of Critical Factors 高密度电路板制造过程中的机械缺陷:关键因素的实验分析

Mechanics of Composite Materials and Structures Pub Date : 2001-01-01 DOI: 10.1080/10759410119256

G. Tani, R. Bedini, M. Presenti, S. Panchetti

{"title":"Mechanical Defects Deriving from the Manufacturing Process of High-Density Electronic Boards: Experimental Analysis of Critical Factors","authors":"G. Tani, R. Bedini, M. Presenti, S. Panchetti","doi":"10.1080/10759410119256","DOIUrl":"https://doi.org/10.1080/10759410119256","url":null,"abstract":"Current market demand calls for electronic boards that are increasingly sophisticated, of high technological content, with high standards of quality and reliability, and cost as low as possible. The high-density electronic boards produced for applications in the biomedical, aerospace, telecommunications, and automation industries are designed using sophisticated procedures that yield optimum results with regard to electronic performances. However, the physical/mechanical and thermal aspects involved in the practical realization of the boards are still based on technological processes that are not as well controlled or as well known with regard to sensitivity to the various characteristic parameters. This results in a high rate of defects occurring in the case of particularly critical boards, due to which finished boards are frequently rejected at inspection or even in service, with significant financial loss. A study has been conducted focusing on qualitative and quantitative analysis of the deformation, and on twisting deformation in particular, of semifinished products during the manufacturing process. A specific procedure has been developed for making measurements and acquiring experimental data, in a research activity commissioned by an Italian company which manufactures electronic boards. Processing of the data and subsequent analysis of the results has made it possible to analyze the production stages having the greatest influence of the extent of the final deformation.","PeriodicalId":111254,"journal":{"name":"Mechanics of Composite Materials and Structures","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133583358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Fracture Energy of Steel Fiber-Reinforced Concrete 钢纤维混凝土的断裂能

Mechanics of Composite Materials and Structures Pub Date : 2001-01-01 DOI: 10.1080/10759410119428

J. A. O. Barros, J. Sena Cruz

{"title":"Fracture Energy of Steel Fiber-Reinforced Concrete","authors":"J. A. O. Barros, J. Sena Cruz","doi":"10.1080/10759410119428","DOIUrl":"https://doi.org/10.1080/10759410119428","url":null,"abstract":"Steel fiber-reinforced concrete (SFRC) is a cementitious material reinforced with discrete fibers. The energy absorption capacity is the main material property benefited by fiber reinforcement. Closed-loop servo-controlled equipment should be used to evaluate this property. The tests should be carried out using displacement control in order to obtain the postpeak force- displacement relationship (tensile strain-softening branch). To assess the fracture energy of SFRC, three-point bending tests were carried out using displacement control. Series of notched beams reinforced with 30, 60, and 90 kg/m3 of hooked-end steel fibers were tested. Besides the energy dissipated in fracturing the concrete, the energy determined from the force-displacement relationship can also include the energy absorbed during nonlinear behavior of concrete in compression. Ductile materials, such as concrete reinforced with a high content of fibers, develop large deflections before exhausting their energy absorption capacity. In these cases, the \"fixed\" points of the bar supporting the displacement transducer may not remain fixed, adding an extra deflection into the control displacement transducer and thus leading to incorrect evaluation of the fracture energy. These factors are analyzed in the present work in order to assess the suitability of the specimen dimensions and the test procedures for evaluating the fracture energy of SFRC.","PeriodicalId":111254,"journal":{"name":"Mechanics of Composite Materials and Structures","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126146461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 65

On Initial Postbuckling of Composite Plate Assemblies by Semianalytical Procedure 复合材料板组件初始后屈曲的半解析方法

Mechanics of Composite Materials and Structures Pub Date : 2001-01-01 DOI: 10.1080/10759410121029

Eugenio Ruocco, Vincenzo Minutolo

引用次数: 10