Structural Analysis of Historical Constructions - SAHC 2023 - Volume 1
Structural Analysis of Historical Constructions - SAHC 2023 - Volume 1
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历史建筑的结构分析 - SAHC 2023 - 第 1 卷
DOI：
10.1007/978-3-031-39603-8_34
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发表时间：
2024
期刊：
影响因子：
--
通讯作者：
Judd M
中科院分区：
文献类型：
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作者：
Judd M
识别现有砌体结构中砂浆的力学性能具有挑战性。虽然可以在实验室中提取和测试这些装置以进行鉴定，但对砂浆进行取样往往是不可行的。本文开发了一种新的砂浆原位识别程序，使用表面应变测量和单位的机械性能的知识。它利用虚场法（VFM）算法，该算法可以从应变和载荷信息直接识别材料特性。在这个新的应用中，VFM被修改为仅使用单元特性来识别砂浆的机械特性，而不依赖于加载信息。这种处理方法有助于消除在平千斤顶试验中遇到的重大载荷不确定性。为了探索这种方法的可行性，一个三维有限元模型的砖砌体墙的微尺度表示。砖和砂浆被指定为各向同性和线弹性材料属性。施加覆盖层和现场平千斤顶荷载。由此产生的表面应变，由于千斤顶加载获得;这些模拟全场测量，可以使用数字图像相关。修改后的VFM方法，然后应用，其中一个很好的协议之间获得的估计和真实的杨氏模量的砂浆。定量分析了单元性质误差和测量噪声对辨识结果的影响，表明了辨识方法的鲁棒性。
Identifying the mechanical properties of mortar in existing masonry structures is challenging. While units can be extracted and tested in the laboratory for identification purposes, sampling of mortar is often unfeasible. This paper develops a new in-situ identification procedure for mortar, using surface strain measurements and knowledge of the mechanical properties of the unit. It makes use of the Virtual Fields Method (VFM) algorithm, which enables the direct identification of material characteristics from strain and loading information. In this new application, the VFM is modified to identify the mechanical properties of mortar using unit properties only, without recourse to loading information. This treatment helps eliminate the significant loading uncertainties encountered during flat jack tests. To explore the feasibility of this approach, a three-dimensional finite element model with a microscale representation of a brick masonry wall is constructed. Bricks and mortar are assigned isotropic and linear elastic material properties. Overburden and in-situ flat jack loads are applied. The resulting surface strains due to jack loading are obtained; these simulate full-field measurements that can be obtained using Digital Image Correlation. The modified VFM approach is then applied, where an excellent agreement was obtained between the estimated and true Young's modulus of the mortar. The influence of errors in unit properties and measurement noise on identification results was quantified and indicate the robustness of the identification procedure.