Recent Advances in Solids and Structures最新文献_第9页

Buckling Characteristics of Regular and Irregular Asymmetric Laminated Composites 规则和不规则非对称层合复合材料的屈曲特性

Recent Advances in Solids and Structures Pub Date : 1998-11-15 DOI: 10.1115/imece1998-0883

A. Vinogradov

引用次数: 0

Comparison of FEA and LPT Based Failure Analysis of P75 Graphite/934 Epoxy Composites 基于FEA和LPT的P75石墨/934环氧复合材料失效分析比较

Recent Advances in Solids and Structures Pub Date : 1998-11-15 DOI: 10.1115/imece1998-0889

K. Rigas, R. Greif, A. Saigal

{"title":"Comparison of FEA and LPT Based Failure Analysis of P75 Graphite/934 Epoxy Composites","authors":"K. Rigas, R. Greif, A. Saigal","doi":"10.1115/imece1998-0889","DOIUrl":"https://doi.org/10.1115/imece1998-0889","url":null,"abstract":"\u0000 A comparison between a micro-mechanical finite element model (FEM) and the macro-mechanical laminated plate theory (LPT) has been undertaken to investigate the failure of an 8-ply [0/0/90/90]s P75 Graphite/934 Epoxy composite subjected to mechanical and thermal loads. This study deals with the initiation of failure, ultimate failure, and resulting stresses at each failure, as well as the effect of thermal residual stresses on the failure of the composite material. Thermal residual stresses develop as a result of the difference in the coefficients of thermal expansion of the fiber and the matrix, and the operating (75°F) and stress-free or cure temperature (350°F). Relationships between the boundary condition of the FEM and LPT are also explored. The ANSYS finite element program has been used in this research. The initiation of failure is based on the ultimate radial stress criterion developed by Bowles and Griffin. For LPT analysis, the first-ply failure and consequent failures are derived using the Tsai-Wu failure theory. The analyses indicate intermediate degradation of the laminate as the applied stress/strain is increased. This information is used to predict the loss in overall stiffness as a function of loading.","PeriodicalId":270413,"journal":{"name":"Recent Advances in Solids and Structures","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134004682","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: 1

Probabilistic Estimation of the Effect of Dimensional Tolerance for Turbine/Compressor Blade Attachment 涡轮/压气机叶片附件尺寸公差影响的概率估计

Recent Advances in Solids and Structures Pub Date : 1998-11-15 DOI: 10.1115/imece1998-0907

Murari P. Singh

{"title":"Probabilistic Estimation of the Effect of Dimensional Tolerance for Turbine/Compressor Blade Attachment","authors":"Murari P. Singh","doi":"10.1115/imece1998-0907","DOIUrl":"https://doi.org/10.1115/imece1998-0907","url":null,"abstract":"\u0000 Root attachments of rotating blades of a turbine or a compressor often have multiple lobes. These lobes fit into a matching groove in a rotating disk. Dimension of these lobes, in general, will not be identical for each blade. However, these dimensions will be within manufacturing tolerance. The resulting dimensional fit becomes random in statistical sense within the specified tolerance. Thus precise dimension is unknown even if it is assured to be within the specified tolerance band.\u0000 This creates the possibility that for a given blade all the lobes might not be in contact i.e. there might be a gap in the joint. This also means that lobes will carry unequal load. The gap condition may be different for each blade. As the rotational speed increases, each gap will start closing and ideally will eventually close.\u0000 Description of a method to assess the influence of manufacturing tolerances on the reliability of such a joint for disk-blade assembly is presented. The resulting estimated stress as a function of rotating speed and tolerance stacking is also presented. The stress result is combined with probabilistic analysis that yields the probability for stress to be within a predetermined amount thus providing a measure of success.","PeriodicalId":270413,"journal":{"name":"Recent Advances in Solids and Structures","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114431500","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: 1

Effects of Bolt Threads on the Stiffness of Bolted Joints 螺栓螺纹对螺栓连接刚度的影响

Recent Advances in Solids and Structures Pub Date : 1998-11-15 DOI: 10.1115/imece1998-0894

T. F. Lehnhoff, Bradley A. Bunyard

{"title":"Effects of Bolt Threads on the Stiffness of Bolted Joints","authors":"T. F. Lehnhoff, Bradley A. Bunyard","doi":"10.1115/imece1998-0894","DOIUrl":"https://doi.org/10.1115/imece1998-0894","url":null,"abstract":"\u0000 Axisymmetric finite element analysis (fea) was performed on bolted joints to determine the effects of the threads on the bolt and member stiffnesses. For steel members, the member stiffness decreased 37.1, 37.7, 38.2, 41.0, and 49.4 percent for the 24, 20, 16, 12, and 8 mm diameter bolts, as the magnitude of the external load was increased. The external load was increased from zero to the value that caused the bolt force to equal its proof strength. The member stiffness for aluminum members decreased by 22.7 and 29.9 percent for the 24 and 20 mm bolts. The cast iron members had decreases of 26.9 and 32.3 for the 24 and 20 mm bolts. Likewise, the aluminum/cast iron members decreased in stiffness by 25.5 and 30.0 percent for the 24 and 20 mm bolts. The member stiffness with no external load applied decreased by approximately 65 percent when changing from steel to aluminum members, 53 percent from steel to cast iron and 60 percent from steel to aluminum/cast iron. Bolt stiffness varied less than 1.4 percent over the total range of the externally applied load for each of the bolted joint models. The decrease in bolt stiffness for the 24 and 20 mm diameter bolts was approximately 4 percent when changing from steel to aluminum members, 7 percent when changing from steel to cast iron members, and 8 percent when changing from steel to aluminum/cast iron members. Comparison is made to research results which did not include the influence of the threads.","PeriodicalId":270413,"journal":{"name":"Recent Advances in Solids and Structures","volume":"213 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122840822","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: 6

A Solid-Fluid Coupling Computing Method for Design High Speed Spindle Cooling System 高速主轴冷却系统设计中的固流耦合计算方法

Recent Advances in Solids and Structures Pub Date : 1998-11-15 DOI: 10.1115/imece1998-0903

D. S. Liu, T. C. Lee

引用次数: 1

Radiated Noise From a Clamped Circular Plate-Shaft System 夹紧圆形板轴系统的辐射噪声

Recent Advances in Solids and Structures Pub Date : 1998-11-15 DOI: 10.1115/imece1998-0901

C. Park, K. Grosh

引用次数: 1

Application of Topology and Finite Element Shape Optimizations in the Design of a Pusher for a Crimp Machine 拓扑优化与有限元形状优化在卷边机推杆设计中的应用

Recent Advances in Solids and Structures Pub Date : 1998-11-15 DOI: 10.1115/imece1998-0896

M. Krishna

引用次数: 0

The Effects of Critical Stitching Parameters on a Stitched Composite Laminate 关键拼接参数对复合材料层合板拼接性能的影响

Recent Advances in Solids and Structures Pub Date : 1998-11-15 DOI: 10.1115/imece1998-0905

Tien-Szu Pan, P. Herrington

引用次数: 0

A Study of Residual Stress and Property Mismatch on SIF Distributions for Cracks Parallel to and Within Bondlines 平行键合线及键合线内裂纹SIF分布的残余应力及性能失配研究

Recent Advances in Solids and Structures Pub Date : 1998-11-15 DOI: 10.1115/imece1998-0880

C. Smith, E. F. Finlayson, C. Liu

引用次数: 0

Impact Damage Resistance of Aluminum Alloy Foams 铝合金泡沫的抗冲击损伤性能

Recent Advances in Solids and Structures Pub Date : 1998-11-15 DOI: 10.1115/imece1998-0888

Jametta McRae, A. Kelkar, C. Grace, W. Craft, Tony Giamei

{"title":"Impact Damage Resistance of Aluminum Alloy Foams","authors":"Jametta McRae, A. Kelkar, C. Grace, W. Craft, Tony Giamei","doi":"10.1115/imece1998-0888","DOIUrl":"https://doi.org/10.1115/imece1998-0888","url":null,"abstract":"\u0000 While some polymers are engineered to improve strength and endurance under elevated temperatures, these same materials are costly both economically and environmentally with the latter of the two stimulating the interest for this study. Polymers, more specifically foam cells are generally flame retardant. When ignited, toxins such as fluorine, bromine and other metallic salts are given off in the air. This poses potential environmental hazards. However, metallic materials (Aluminum) with their high strength, stiffness and ductility are much more environmentally friendly. Even if alloyed with appropriate compounds, the resulting core material could be melted down, separated then cast into new stock. Moreover, the use of an alloyed material can generally enhance the strength and stiffness of sandwich composite structures so essential in aerospace applications.\u0000 United Technologies Research Center provided a plate of Aluminum alloy foam for impact testing by North Carolina A&T Researchers and graduate students. The material was provided by Austrian Metals Co. (AMAG) to UTRC under ONR Contract # N00014-95-C-0231, Thompson & Renauld (1997). All specimens were cut from one sample of nominal dimensions of 20 inches by 20 inches by 0.65 inches in thickness. The sample mass was 3142 grams and the apparent density was 0.737 g/cc. The chemical composition is close to that of 6061. The sheet sample was formed by AMAG and heat treated to T5 specifications consisting of 14 hours in a furnace at 160 °C.\u0000 Generally the bending stiffness and failure mechanisms were substantially different from those of polymeric foam sandwich cores made of Rohacell, a polymethacrylimide (PMI) foam in a prior study, Craft et al (1997). Rohacell is an easily machined, but a hygroscopic form with low shear strength and stiffness, but it and many other organic foams have a relatively uniform cellular construction in a wide variety of densities.","PeriodicalId":270413,"journal":{"name":"Recent Advances in Solids and Structures","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121208828","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