共查询到20条相似文献,搜索用时 15 毫秒
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为研究纳米梁的力学特性,采用SOI晶圆制备了硅双端固支梁纳米梁,利用典型的原子力显微镜(AFM)弯曲测试方法测试了硅纳米梁〈100〉晶向的杨氏模量.AFM悬臂探针定位在纳米梁的中点处向下移动,纳米梁受到挤压发生弹性形变,形变过程存在一个最大形变点,在该点后,纳米梁被挤压在SOI硅片底层硅上.最大形变前的测试数据用于计算力-位移曲线斜率,最大形变后的测试数据用于计算探针的灵敏度,其实验值分别为0.792N/m和81.83nm/V.最终得到的杨氏模量为104GPa,该值小于体硅的杨氏模量,表面应力和缺陷可能是导致实验值偏小的原因. 相似文献
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The Young's modulus of graphene is estimated by measuring the strain applied by a pressure difference across graphene membranes using Raman spectroscopy. The strain induced on pressurized graphene balloons can be estimated directly from the peak shift of the Raman G band. By comparing the measured strain with numerical simulation, we obtained the Young's modulus of graphene. The estimated Young's modulus values of single- and bilayer graphene are 2.4 ± 0.4 and 2.0 ± 0.5 TPa, respectively. 相似文献
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利用蚀刻硅技术制造的微机械构件 ,由于特殊的制作工艺而需要对其材料的机械性能如杨氏模量等进行测试。这是随微机械技术的产生而提出的一个新课题。文章综述了微机械材料杨氏模量的静态测试法。提出了微机械材料杨氏模量的动态测试法———静电激振法。这种方法具有测试装置简单、测量容易、适应性广等特点 相似文献
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Measuring True Young's Modulus of a Cantilevered Nanowire: Effect of Clamping on Resonance Frequency
The effect of clamping on resonance frequency and thus measured Young's modulus of nanowires (NWs) is systematically investigated via a combined experimental and simulation approach. ZnO NWs are used in this work as an example. The resonance tests are performed in situ inside a scanning electron microscope and the NWs are cantilevered on a tungsten probe by electron-beam-induced deposition (EBID) of hydrocarbon. EBID is repeated several times to deposit more hydrocarbons at the same location. The resonance frequency increases with the increasing clamp size until approaching that under the "fixed" boundary condition. The critical clamp size is identified as a function of NW diameter and NW Young's modulus. This work: 1) exemplifies the importance of considering the effect of clamping in measurements of Young's modulus using the resonance method, and 2) demonstrates that the true Young's modulus can be measured if the critical clamp size is reached. Design guidelines on the critical clamp size are provided. Such design guidelines can be extended to other one-dimensional nanostructures such as carbon nanotubes. 相似文献
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In this paper, yet another method for evaluating the elastic modulus for human bones is introduced and investigated. This method adopts the Jankowski and Tsakalakos strain energy function in which, the Born-Mayer energy term is the predominant term for calculations the elastic constants. By taking accounts the directional aspects of the spatial structure of bones, we obtain different values for the Young's modulus depending on the direction of the applied force with respect to the material's structure. The inverse problem analyzed in this paper is solved by inversion of the experimental data. An efficient stopping criterion is adopted to cease the iterative process in order to retrieve stable numerical solutions. The numerical implementation of the aforementioned method is realized by employing a genetic algorithm. 相似文献
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原子力显微镜微悬臂梁是微纳米领域重要的微力传感器,而微悬臂梁的杨氏模量又是决定其力学性能的重要参数.由于微悬臂梁的尺寸处于微米级,有些特征尺寸甚至达到纳米级,常规的测试结构材料特性的检测方法已经难以满足需求,急需研究新的测试方法和装置对微悬臂梁的机械特性进行研究和分析.本文提出了一种基于微悬臂梁振动固有频率测试的杨氏模量测试方法.使用本方法时,首先建立待测微悬臂梁在空气中的振动模型,并使用数值仿真的方法计算结构尺寸相同但杨氏模量不同的各种微悬臂梁在空气中的振动固有频率,然后实际测量微悬臂梁的振动固有频率,和实验结果最接近的仿真结果所对应的杨氏模量参数就是待测微悬臂梁的杨氏模量.本文最后对Mikromaseh公司生产的NSC型探针的杨氏模量进行了测试,实验结果证实了本文提出的方法的正确性. 相似文献
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Hao-Miao Zhou Fang Li Qiang Ye Ji-Xiang Zhao Zhe-Lei Xia YingTang Jing Wei 《计算机、材料和连续体(英文)》2009,13(3):235-248
At present, there are many methods about Young's modulus measurement of thin films, but so far there is no recognized simple, non-destructive and cheaper standard measurement method. Considering thin films with various thicknesses were sputter deposited on the magnetostrictive resonator and monitoring the resonator's first-order longitudinal resonant frequency shift both before and after deposition induced by external magnetic field, an Young's modulus assessing method based on classical laminated plate theory is presented in this paper. Using the measured natural frequencies of Au, Cu, Cr, Al and SiC materials with various thicknesses in the literature, the Young's modulus of the five materials with various thicknesses are calculated by the method in this paper. In comparison with the Young's modulus calculated by the other methods, it is found that the calculated Young's modulus for various thicknesses are in good agreement with the Young's modulus values in the literature. Considering the simple and non-destructive characteristics of this method, which can effectively describe the effect of the thickness on the Young's modulus, it has the potential to become a standard assessing method of thin film Young's modulus. 相似文献
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Abstract: This paper focuses on the investigation of the three-point bending tensile strength of Dionysos marble. Using the classical relationship obtained from the theory of elasticity, the effect of the span length, the thickness/width ratio and the orientation of the specimens in the indirect tensile strength were investigated. In total, 42 experiments were carried out, divided in three sets of specially designed beams. Finally, the calculated bending tensile strength is compared with the corresponding value obtained from Brazilian indirect tension as well as ring tests. 相似文献
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Amin Montazeri Ehsan Bahmanpour Majid Safarabadi 《Advanced Engineering Materials》2023,25(17):2300273
Cellular hexagonal (conventional) and re-entrant (auxetic) honeycombs are applicable in automotive, construction, and protective engineering. Auxetic structures own excellent energy absorption and flexural behavior due to their special deformation under loading. This work explores the performance of additively manufactured polylactic acid (PLA)- and thermoplastic polyurethane (TPU)-based hexagonal and re-entrant honeycombs under flexural loading via experimental three-point bending (TPB) tests and finite-element analysis (FEA). 3D-printed conventional and auxetic cellular structures are filled with polyurethane (PU) foam and their energy absorption capacity and flexural modulus are compared with hollow structures. The results reveal that TPU-based structures’ energy absorption capacity and flexural modulus improve significantly, whereas the PLA-based structures’ performance deteriorates when filled with PU foam. Moreover, re-entrant honeycombs are better reinforced with foam in comparison to the hexagonal honeycombs, as the re-entrant's unit cell is more spacious than the hexagonal unit cell. Finally, parametric studies are performed via FEA to investigate the influence of geometric parameters of structures and flexural loading setup on the performance of the honeycombs, showing that structures with thicker struts and higher cell angle can act stiffer under TPB. The outcomes of this research indicate the promising performance of foam-filled TPU-based auxetic structures. 相似文献
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Nestor Iguiiz Riccardo Frisenda Rudolf Bratschitsch Andres Castellanos‐Gomez 《Advanced materials (Deerfield Beach, Fla.)》2019,31(10)
Measuring the mechanical properties of 2D materials is a formidable task. While regular electrical and optical probing techniques are suitable even for atomically thin materials, conventional mechanical tests cannot be directly applied. Therefore, new mechanical testing techniques need to be developed. Up to now, the most widespread approaches require micro‐fabrication to create freely suspended membranes, rendering their implementation complex and costly. Here, a simple yet powerful technique is revisited to measure the mechanical properties of thin films. The buckling metrology method, that does not require the fabrication of freely suspended structures, is used to determine the Young's modulus of several transition metal dichalcogenides (MoS2, MoSe2, WS2, and WSe2) with thicknesses ranging from 2 to 10 layers. The obtained values for the Young's modulus and their uncertainty are critically compared with previously published results, finding that this simple technique provides results which are in good agreement with those reported using other highly sophisticated testing methods. By comparing the cost, complexity, and time required for the different methods reported in the literature, the buckling metrology method presents certain advantages that make it an interesting mechanical test tool for 2D materials. 相似文献