摘要
小试样蠕变试验技术,在服役构件力学性能测试中得到了广泛的发展与应用。目前已有小尺寸单轴试验、小冲杆试验、剪切冲压试验、压痕试验、三点弯试验、悬臂梁试验、固支直杆弯曲试验、圆环试验和双杆试样等方法。基于上述小试样方法,重点从试样尺寸、应力状态、关联式类型、蠕变性能、变形测量和影响因素等方面,全面地综述不同小试样测量材料蠕变性能的方法和结果的异同。通过对比发现,不同类型试样所得蠕变曲线差异较大。小冲杆试样的数据转换过程较为复杂,试验过程中影响因素较多。悬臂梁试样和圆环试样的等效标距较大,变形测量误差小。三点弯、悬臂梁和圆环试样,蠕变试验过程中存在大变形效应,可采用临界载荷法预先控制试验载荷范围。固支直杆弯曲试样方法对摩擦的敏感性较低,可获得较为准确的断裂数据。所得结论为选择合适的小试样方法测试材料的蠕变性能提供理论指导和依据。
The application of small specimen creep test techniques in determination of creep properties of materials in-service has been increasing. There exists a number of small specimen creep testing techniques, such as sub-size uniaxial specimen, small punch specimen, shear punch specimen, impression specimen, three-point bending specimen, cantilever beam specimen, beam specimen with fixed constraint, circular ring specimen and tow-bar specimen. The diversity in specimen types and dimensions will affect the evaluation of creep properties. It is hence necessary to make a comparison among different small specimen creep tests. A comprehensive review has been made on the effect of the specimen dimension, stress state, conversion equation, creep properties, strain sensitivity and other influence factors. The results show that different small specimens result in different creep curves. Influenced by many factors, the small punch specimen has a very complicated data interpretation. With a large equivalent gauge length, the cantilever beam and circular ring specimens can obtain rather accurate creep data. Large deformation effect exists for the three-point bending, cantilever beam and circular ring specimens, which can be controlled by the critical load approach. Because of the low frictional sensitivity, the beam specimen with fixed constraint can obtain creep rupture data of high accuracy. A code of practice is then recommended for selecting a proper small specimen to evaluate the creep properties for in-service components.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2015年第6期9-18,共10页
Journal of Mechanical Engineering
基金
国家自然科学基金(11472105)
上海市浦江人才计划(14PJD015)
质检公益性行业科研专项资金(201410024)资助项目
关键词
小试样
蠕变性能
性能测试
试样选取
尺寸效应
small specimen
creep properties
properties test
specimen selection
size effect
作者简介
庄法坤，男，1987年出生，博士。主要研究方向为高温服役结构材料蠕变性能测试技术。E-mail：zhuangfakun@126．com
涂善东（通信作者），男，1961年出生，博士，教授，博士研究生导师。主要研究方向为高温环境下的结构设计理论与寿命预测技术、结构完整性监测、微化学机械系统（MCMS）、先进能源材料与装备。E-mail：sttu@ecust．edu．cn
