V(f, z)分析方法在小尺寸材料弹性常数测量中的应用
Measurement of Elastic Constants of the Smaller-specimen Materials With V(f) Analytical Method
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摘要: 针对小尺寸材料弹性常数的测量,提出了一种频域处理方法——V(f,z)分析方法.V(f,z)分析方法基于声学显微镜技术,使用线聚焦聚偏二氟乙烯(PVDF)探头,测定材料的表面波波速,计算材料的弹性常数.采用该分析方法对块体不锈钢试件的弹性常数进行了测量,测量结果与理论值相吻合.误差分析结果表明,V(f,z)分析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5%,能满足工程和科学研究的要求.此外,V(f,z)分析方法可测得不同频率的频散曲线,不仅适用于块体材料,而且适用于薄板、涂层等具有频散特性的材料,这为进一步测量薄板材料和涂层材料的弹性常数奠定了分析基础.Abstract: The V(f) analytical method is an analytical method of frequency domain,and can be applied to measure the elastic constants of the smaller-specimen materials.Based on the technology of acoustic microscope,the line focus polyvinylidend fluoride (PVDF) transducer was applied to measure the longitudinal wave.The surface wave velocity could be got by the V(f) analytical method,then the elastic constants were calculated.Elastic constants of the stainless steel were measured,and results were consistent with theoretical values.The error analysis shows that this method has a higher accuracy and the errors of Poisson's ratio and Young's modulus is within 5%,which means that this method can meet the need of engineering and scientific research.Moreover,this method can be used to measure the thin plate and coating materials,which lays the foundation for further measuring the elastic constants of thin plate and coating materials.