Manufacturing with Light Phase 2: Photoelasticity for sub-surface stress measurements in structural ceramics coating systems

光阶段 2 制造：结构陶瓷涂层系统中亚表面应力测量的光弹性

基本信息

批准号：
EP/N018249/1
负责人：
Andrew Moore
金额：
$ 55.53万
依托单位：
Heriot-Watt University
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2016
资助国家：
英国
起止时间：
2016 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FN018249%2F1
关键词：
Manufacturing Light Phase Photoelasticity sub

项目摘要

Birefringence is a difference in refractive index that occurs along different axes in a material. In some materials this effect is intrinsic due to the atomic structure. In other materials, artificial birefringence can be induced by a mechanical stress that produces anisotropies in the material. Polarized waves travel at different velocities through the stressed regions depending on their polarization direction. This phenomenon is exploited in the well-established technique of photoelasticity, in which a model of the component of interest is made in an optically transparent plastic material and placed between polarizing optics. The induced birefringence is directly proportional to the stress experienced at a given point: contours of constant difference in the principal stresses and contours of the principal stress direction appear as fringe patterns. The technique has played a fundamental role in experimental mechanics, design and manufacturing.This project is concerned with measuring the stress-induced birefringence in materials that are opaque at visible wavelengths. We will use THz illumination up to 7.5 THz where some fraction is transmitted through a range of non-polar materials including ceramics, plastics and composites. Measuring the stress-induced birefringence will provide information on the internal stress distribution in real components that are opaque at visible wavelengths, removing the need to model it in transparent plastic as in photoelasticity. Measurement from the real components also enables direct validation of numerical models. These new techniques will enable in-process control during manufacturing applications and in-service quality assurance, for a range of materials where this is not currently available, enabling step changes in the manufacturing processes used and the components that can be produced.

双折射是沿材料中不同轴的折射率的差异。在某些材料中，由于原子结构，这种作用是固有的。在其他材料中，可以通过在材料中产生各向异性的机械应力来诱导人造双折射。偏振波在不同速度通过压力区域的极化方向传播。这种现象是在光弹良好的技术中利用的，其中感兴趣的组成部分是在光学透明的塑料材料中制成的，并将其放置在偏振光学之间。诱导的双折射与给定点上所经历的应力直接成正比：主应力方向的主要应力和轮廓恒定差异的轮廓似乎是条纹模式。该技术在实验力学，设计和制造中发挥了基本作用。该项目与测量可见波长不透明的材料中应力诱导的双折射相关。我们将使用高达7.5 THz的THZ照明，其中一些分数通过一系列非极性材料（包括陶瓷，塑料和复合材料）传输。测量应力诱导的双折射将提供有关可见波长下不透明的真实组件中内部应力分布的信息，从而消除了将其以透明塑料对其进行建模的需求，例如光弹性。实际组件的测量还可以直接验证数值模型。这些新技术将在制造应用程序和在职质量保证期间实现过程中的控制，对于目前尚不可用的一系列材料，可以改变所使用的制造过程和可以生产的组件的步骤。