失效分析与预防最新文献

The Interaction of Crack and Creep in Cross-Ply Composites 交叉层复合材料中裂纹与蠕变的相互作用

失效分析与预防 Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0862

Z. Gao

{"title":"The Interaction of Crack and Creep in Cross-Ply Composites","authors":"Z. Gao","doi":"10.1115/imece1996-0862","DOIUrl":"https://doi.org/10.1115/imece1996-0862","url":null,"abstract":"\u0000 For cross-ply laminates micro-matrix cracks in the 90° plies and creep deformation of the 0° and 90° plies are two forms of damages which affects the long-term durability of the materials. In this paper, a general framework for the analysis of cross-ply laminates with matrix cracks and creep deformation is proposed. For this purpose admissible stress fields are constructed which satisfy equilibrium and all boundary and interface conditions. The principle of minimum complementary energy is utilized to derive a differential equation for the stress function from which the stress field of the composite can be derived. The inhomogeneous term of the differential equation involves the creep strains which are loading history dependent. The Green’s function of the differential equation is then obtained. Using the Green’s function and a constitutive equation, two-dimensional stress and strain states in the composites at any time are represented through an integral of the Green’s function and the accumulated creep strains. This new analysis takes into consideration the microcrack-microcrack interaction, as well as the interaction between the microcracks and the creep deformation, and provides a point-wise stress field instead of average stress field as most of the analytical approaches yield.\u0000 The interactions of matrix cracks and creep deformation of an eight-harness satin weave (8H SW) Nextel 610/Aluminosilicate ceramic matrix composite is studied using the proposed model. The predicted creep strain of the composite shows good correlation with experimental data at different levels of temperature and stress conditions.","PeriodicalId":64773,"journal":{"name":"失效分析与预防","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82827089","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

Contact Pressure Distribution in a Key Joint 键接头接触压力分布

失效分析与预防 Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0858

K. Varadi, D. Verghese, S. Engelbrecht

引用次数: 0

Three-Dimensionai Finite Element Analysis of Stress Response in Adhesive Butt Joints Subjected to Impact Tensile Loads 碰撞拉伸载荷作用下粘接对接接头应力响应的三维有限元分析

失效分析与预防 Pub Date : 1996-11-17 DOI: 10.1080/00218469908015919

T. Sawa, Hirohisa Okuno, I. Higuchi

{"title":"Three-Dimensionai Finite Element Analysis of Stress Response in Adhesive Butt Joints Subjected to Impact Tensile Loads","authors":"T. Sawa, Hirohisa Okuno, I. Higuchi","doi":"10.1080/00218469908015919","DOIUrl":"https://doi.org/10.1080/00218469908015919","url":null,"abstract":"\u0000 The stress wave propagation and the stress distribution in adhesive butt joints of similar adherends subjected to impact loads are analyzed using three-dimensional finite-element method (FEM). The code employed is DYNA3D. An impact load is applied to a joint by dropping a weight. An adherend of a joint is fixed and the other adherend to which a bar is connected is impacted by the weight. The height of the weight is changed. The effect of the ratio of the adherends’ the adhesive’s Young’s modulus, the adhesive thickness and the geometry of T-shape adherends on the stress wave propagation at the interface are examined. It is found that the maximum stress is caused at the interface of the adherend subjected to an impact load. In the case of T-shape adherend, it is seen that the maximum stress is caused near the center of the interface and that it increases as Young’s modulus of the adherends increases. In the special case where the web length of T-shape adherends equals to the interface length, it is seen that the singular stress occurs at the edge of the interfaces and it increases as Young’s modulus of adherends decreases. The maximum principal stress increases as the adherends’ thickness increases. In addition, strain response of adhesive butt joints subjected to impact loads was measured using strain gauges. Fairly good agreement is found between the numerical and the measured results.","PeriodicalId":64773,"journal":{"name":"失效分析与预防","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75781914","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: 2

The Selection of Diagnostic Technologies and Sensors for Condition Based Maintenance Systems 基于状态维护系统的诊断技术和传感器的选择

失效分析与预防 Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0865

C. Nemarich, H. R. Hegner, M. Natishan

引用次数: 0

Stress Analysis and Strength of Joints Combining Adhesives With Bolts Subjected to Torsions 胶粘剂与螺栓结合接头在扭转作用下的应力分析与强度

失效分析与预防 Pub Date : 1996-11-17 DOI: 10.1299/KIKAIA.64.2628

M. Yoneno, T. Sawa, Hidekazu Nishijima, M. Matsuo

{"title":"Stress Analysis and Strength of Joints Combining Adhesives With Bolts Subjected to Torsions","authors":"M. Yoneno, T. Sawa, Hidekazu Nishijima, M. Matsuo","doi":"10.1299/KIKAIA.64.2628","DOIUrl":"https://doi.org/10.1299/KIKAIA.64.2628","url":null,"abstract":"\u0000 The stress distributions in joints combining adhesives with bolts are analyzed by using axisymmetrical theory of elasticity as a three-body contact problem when torsion is applied to the joints. The joints consist of two hollow cylinders and they are fastened by a bolt and nut after being joined with an adhesive. When an external torsion is applied to combination joints, an increment / decrement of torsion occurs in the bolt. A method for estimating the variation of torsion in the bolt is proposed. In addition, using the interface stress distribution, a method for predicting strength of the combination joint is proposed. The torsional load produced in the bolt was measured using strain gauges. Strength of the combination joint was also measured. A fairly good agreement was seen between the analytical and the experimental results. It is shown that the increment of torsional load occurs in the bolt is small. It is found that the strength of the combination joints is greater than that of adhesive joints. It is also seen that the combination joint strength increases as the initial clamping force increases and that it is greater than that of bolted joints without adhesives.","PeriodicalId":64773,"journal":{"name":"失效分析与预防","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89351882","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

Two-Dimensional Finite Element Thermal Stress Analysis of Butt Adhesive Joint in Steady Temperature State 对接胶接头稳态二维有限元热应力分析

失效分析与预防 Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0855

F. Nakagawa, T. Sawa, Y. Nakano, M. Katsuo

{"title":"Two-Dimensional Finite Element Thermal Stress Analysis of Butt Adhesive Joint in Steady Temperature State","authors":"F. Nakagawa, T. Sawa, Y. Nakano, M. Katsuo","doi":"10.1115/imece1996-0855","DOIUrl":"https://doi.org/10.1115/imece1996-0855","url":null,"abstract":"\u0000 Thermal stresses of butt adhesive joints in steady temperature state are analyzed using a two-dimensional finite element method (FEM). The results obtained are as follows. The maximum principal thermal stress in the adhesive layer decreases when the ratio of thermal conductivity of an adhesive to that of an adherend approach I. When both adherends arc in the same temperature state, the maximum principal thermal stress in the joint decreases with a decrease of the adhesive thickness. When both adherends are in different temperature states, the maximum principal thermal stress varies with the ratio of the adherend thickness to the adhesive thickness. The maximum principal thermal stress in the joint which is subjected to the uniform temperature change AT is smaller than that in the joint in which the temperature difference of free surfaces of both the adherends is AT. In the experiments, the adhesive layer of the butt adhesive joint was modeled by an epoxide resin plate. The thermal stresses of the joints under steady temperature state were measured by two-dimensional photoelastic experiments. Fairly good agreement was seen between the numerical and the experimental results.","PeriodicalId":64773,"journal":{"name":"失效分析与预防","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78323785","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

Non-Linear Finite Element Analysis of the Contact, Strain and Stress States of a Bolt-Nut-Washer-Compressed Sheet Joint System 螺栓-螺母-垫圈-压片连接系统接触、应变和应力状态的非线性有限元分析

失效分析与预防 Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0857

L. Joanovics, K. Varadi

引用次数: 2

Experience With the Application of Risk Concepts in Developing Equipment Prioritization Systems 风险概念在设备优先排序系统开发中的应用经验

失效分析与预防 Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0866

A. Tallin, M. Conley

{"title":"Experience With the Application of Risk Concepts in Developing Equipment Prioritization Systems","authors":"A. Tallin, M. Conley","doi":"10.1115/imece1996-0866","DOIUrl":"https://doi.org/10.1115/imece1996-0866","url":null,"abstract":"\u0000 As consultants to refining and petrochemical companies, Det Norske Veritas (DNV) has been involved in developing risk based prioritization and management systems for a number of years. This paper follows DNV’s experience as it developed these methods, beginning with the initial concepts through the completion of several projects. The paper discusses some of the efforts that have been made to standardize the application of risk based prioritization.\u0000 In applying risk based inspection, the likelihood and consequence of each individual item is considered and the result is a ranking system that identifies and ranks failures on a uniform scale. In virtually every study DNV has performed, the “Pareto Principle” has been confirmed: at least 80% of a plant’s total risk exposure is due to at most 20% of the equipment. In many plants, the 90% of the risk is due to only 10% of the equipment. The principle is demonstrated here by presenting the overall distributions of risk that have resulted from prioritization studies that DNV has done.\u0000 The highest expected return is produced by prioritizing maintenance and inspection efforts to concentrates on this subset of items.","PeriodicalId":64773,"journal":{"name":"失效分析与预防","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74708022","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

Elasto-Plastic Finite Element Analysis of Isotropic Plates With U-Notches u型缺口各向同性板的弹塑性有限元分析

失效分析与预防 Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0859

N. Arslan, A. Turgut, Erol Sancaktar

引用次数: 1

Experimental Study of Rotor Blade Tip Clearance Control Utilizing Smart Structure Technology 基于智能结构技术的动叶尖间隙控制实验研究

失效分析与预防 Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0864

Y. Lin, C. Wen, B. Choi, D. Saravanos

{"title":"Experimental Study of Rotor Blade Tip Clearance Control Utilizing Smart Structure Technology","authors":"Y. Lin, C. Wen, B. Choi, D. Saravanos","doi":"10.1115/imece1996-0864","DOIUrl":"https://doi.org/10.1115/imece1996-0864","url":null,"abstract":"\u0000 In this paper the experimental development of a simple and effective vibration control scheme for a flexible cantilever beam employing smart structure technology is presented. Our goal is to develop a physically realizable means to actively control turbine rotor blade tip vibration with piezoceramic sensors and actuators. To include the flexible characteristics of rotor blades in our analysis, a flexible cantilever beam is used to simulate the dynamic behavior of the turbine blades due to external disturbances, generated by a magnetic shaker. The shaker was installed near the free end of the flexible beam to maximize the external excitations. Piezoceramic sensor and actuator were used and evenly distributed as elements of the smart structure. The mathematical model of the smart structure including the piezoceramic sensors and actuators was determined by combining both analytical and experimental schemes. Based on the derived experimental dynamic model, a proportional gain feedback controller was implemented to compensate for the vibratory deflections of the underlying structure. The results of the work show that the proposed control methodology along with the smart structure can suppress more than 80% of the measured structural vibration, which is considered satisfactory.","PeriodicalId":64773,"journal":{"name":"失效分析与预防","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81750508","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