The Application of Grid-Based Tactile Pressure Technology to Discontinuous Materials

基于网格的触觉压力技术在不连续材料中的应用

• 批准号: 9908612
• 负责人: Samuel Paikowsky
• 金额: $ 20.63万
• 依托单位: University of Massachusetts Lowell
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-10-01 至 2005-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9908612&HistoricalAwards=false
• 关键词: Application; Grid; Based; Tactile; Pressure

***9908612PaikowskyLarge variation in stress distribution within granular materials is a result oftheir unique characteristics. The stress variations are of great importancefor basic science and many engineering applications. The present research isaimed at the investigation of the stresses developing in granular materialsutilizing grid-based tactile pressure technology. A development of acalibration and interpretation methodology for the tactile sensors isproposed. Experimental program investigating the state of stress in granularmaterials under fundamental and engineering applications is planned.The behavior of discontinuous (discrete, granular) materials is an importantfactor in many disciplines. These materials display unique behavior in the formof volume change during shear and arching. The fundamental mechanism of archingrelates to the ability of discrete units to transfer loads through interactionin a preferable geometry and thus to bridge between the zone (or point) of loadapplication to the zone (or points) of reaction. These features result in aunique load transformation and stress distribution within discontinuousmaterials and on the boundary between them and solid surfaces. Accuratemeasurements of stress distribution are cardinal therefore for theunderstanding of the physical phenomena as well as the evaluation of designcriteria and monitoring performance. The existing methods of evaluating stress distribution in a granular mass relymostly on the use of buried load cells. These measurements are difficult toperform and are limited in their ability to capture the stress variation.A new technology, which makes use of flexible, grid-based, tactile pressuresensors, allows to measure stresses at a large number of points in proximity toone another, hence providing a realistic normal stress distribution. Theirflexibility overcomes the intruding effect introduced by rigid load cells andthus allows for measurements that better represent the existing stressconditions. The application of the tactile pressure technology to granularmaterials requires adaptation and calibration due do its innovative principleof operation. A preliminary viability study was conducted at the GeotechnicalEngineering Research Laboratory at the University of Massachusetts Lowell,which focused on evaluating the tactile sensor technology, overcoming thedifficulties associated with it and utilizing the method in exploratoryapplications. The results of this study have provided the basis for thepresent research.The proposed experimental program includes enhancement of the calibration andtesting of the system followed by basic and applicative research applications. The obtained results and analyses (numerical and analytical) are expected toprovide (a) Basis for the implementation of a new technology to granularmaterials. (b) Significant insight to evaluate current knowledge and (c)Actual stress measurements and behavior of granular materials and structuresfrom a previously unobtained perspective. The use of the technology ineducation is promising, allowing for demonstrations elucidating the concept ofstresses.***

*9908612 Paikowski颗粒材料内部的应力分布变化很大是由于其独特的特性。应力变化对基础科学和许多工程应用都具有重要意义。本研究旨在利用基于网格的触觉压力技术来研究颗粒材料中的应力发展。提出了一种改进的触觉传感器校准和解释方法。研究颗粒材料在基础和工程应用中的应力状态的实验计划正在计划中。在许多学科中，不连续(离散的、颗粒的)材料的行为是一个重要的因素。这些材料在剪切和拱化过程中以体积变化的形式表现出独特的行为。拱形的基本机制与离散单元通过较佳几何形状的相互作用传递荷载的能力有关，从而在施加荷载的区域(或点)与反作用区(或点)之间架起桥梁。这些特点导致了不连续材料内部以及它们与固体表面之间的边界上独特的载荷转换和应力分布。因此，准确测量应力分布对于理解物理现象以及评估设计标准和监测性能至关重要。现有的评价散体应力分布的方法大多采用埋藏式测力计。这些测量很难操作，而且捕捉应力变化的能力有限。一项新技术利用灵活的栅格式触觉压力传感器，允许测量彼此邻近的大量点的应力，从而提供真实的正常应力分布。它们的灵活性克服了刚性称重传感器带来的干扰效应，从而允许测量更好地代表现有的应力条件。触压技术在颗粒材料中的应用，由于其创新的操作原理，需要进行适配和校准。马萨诸塞州洛厄尔大学岩土工程研究实验室进行了一项初步的可行性研究，重点是评估触觉传感器技术，克服与之相关的困难，并将该方法用于探索性应用。本研究的结果为本研究提供了基础。提出的实验方案包括加强系统的校准和测试，以及基础和应用研究应用。所获得的结果和分析(数值和分析)可望为颗粒材料的新技术的实施提供依据。(B)评价现有知识的重要洞察力；(C)颗粒材料和结构的实际应力测量和行为；以及(D)从以前未曾获得的角度进行分析。这项技术在教育中的应用前景看好，可以通过演示来阐明压力的概念。