中文摘要：

介绍了针对小试件材料力学性能测试的特殊需求而设计的超声精密测量系统和测试方法，并进行了实验验证．系统基于声学显微镜技术，利用超声波线聚焦PVDF探头，通过同时测定纵波和漏表面波波速来表征材料的弹性常数等．对不同材料的小试件弹性常数进行了测量，测量结果与常规实验结果和理论值相吻合，表明该方法可行，结果可靠．误差分析结果表明本测试系统及测试方法具有较高的测量精度，泊松比和杨氏模量的测量误差均小于3％，能够满足工程及科学研究的要求．此外，该系统不仅适用于各向同性材料，而且适用于各向异性材料，为进一步评价块体纳米材料制备工艺和表征纳米材料的力学性能奠定了基础．

英文摘要：

It was described and validated the ultrasonic system with a line-focused PVDF transducer for the measurement of the elastic constants of small-size samples. The objective of this system was to measure the elastic constants of limited-size samples with high accuracy on the base of acoustic microscope technology. The elastic constants of aluminum, copper, steel, and titaniumalloy were determined by measuring the velocity of the longitudinal and leak surface waves simultaneously. Results were similar to these obtained by the general test method and the theoretic simulations. This showed that the ultrasonic test method is feasible and the results were reliable. The error analysis showed that the measuring system had a higher accuracy and the errors of Poisson＇ s ratio and Young＇ s modulus was within 3%. This can meet the need of the engineering and scientific research. Moreover, the method can be used to determine elastic constants of both isotropic and anisotropic materials.