权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Inelastic Analysis of Stress-Strain Response in Engineering Ceramics at Elevated Temperatures

高温下工程陶瓷的应力-应变响应的非弹性分析

基本信息

批准号：
03452104
负责人：
HATANAKA Kenji
金额：
$ 4.03万
依托单位：
Yamaguchi University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1992
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-03452104/
关键词：
Sintered Silicon Nitride Ceramics High Temperature Tensile Test Tensile Stress-Strain Response Inelastic Deformation Measurement of Tensile Displacement Elastic-Plastic F.E.M High Temperature Creep High Temperature Fatigue 常圧焼結窒化けん素セラミック

项目摘要

The tensile tests and tensile creep tests were performed for the sintered silicon nitride ceramics at elevated temperatures. The four projections were machined in the gauge length of the specimen, and the displacement was measured between the two projections on one side of the specimen by means of the laser-beam-type extensometer. Furthermore, the new test system was developed for evaluating the fatigue properties of ceramics at elevated temperatures. Then push-pull fatigue tests were performed for the sintered silicon nitride ceramics in the temperature range from room temperature to 1200ﾟC. The results obtained are summarized as follows :1. The tensile stress-strain relationship was markedly influenced by test temperature and displacement rate.2. The nominal stress-strain relationships calculated from the measured load (P)-displacement(delta) relationships were corrected so that the p-delta curve calculated using the elastic-plastic F.E.M agreed with the measured one. The corrected stress-strain relationship seems to give the intrinsic relationship of sintered silicon nitride ceramics at elevated temperatures.3. The creep curves of sintered silicon nitride ceramics exhibited the transient creep period, being followed by the steady creep period.4. According to the relationships between the minimum creep strain rate and nominal stress plotted in double logarithmic scales, the data could be fitted by two straight lines, and their slopes are larger in the higher stress region than in the lower stress region.5. The relationships between stress amplitude and number of cycles to failure showed the shape of a so called S-N curve. The slope of S-N curve, however, had a tendency to decrease with increase in test temperature.

对烧结氮化硅陶瓷进行了高温拉伸试验和拉伸蠕变试验。在试样的标距长度中加工四个突起，并通过激光束型引伸计测量试样一侧上的两个突起之间的位移。此外，新的测试系统开发的陶瓷在高温下的疲劳性能进行评估。在室温至1200 ℃的温度范围内对烧结氮化硅陶瓷进行了推拉疲劳试验。主要研究结果如下：1.拉伸应力-应变关系受试验温度和位移速率的显著影响.对根据实测载荷（P）-位移（δ）关系计算的标称应力-应变关系进行了校正，以使使用弹塑性有限元法计算的p-δ曲线与实测曲线一致。修正后的应力-应变关系似乎给出了烧结氮化硅陶瓷在高温下的本征关系.烧结氮化硅陶瓷的蠕变曲线表现为瞬态蠕变，随后是稳态蠕变.根据双对数标度绘制的最小蠕变应变率与名义应力之间的关系，数据可以用两条直线拟合，且其斜率在高应力区比在低应力区大。5.应力幅值与失效循环次数的关系呈S-N曲线。S-N曲线的斜率随试验温度的升高而减小。