Substrate membrane bearing close‐packed array of micron‐level pillars incrassates air‐exposed three‐dimensional epidermal equivalent model

Author(s):  
Junichi Kumamoto ◽  
Koji Fujimoto ◽  
Yasuaki Kobayashi ◽  
Kota Ohno ◽  
Masaharu Nagayama ◽  
...  
Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 134
Author(s):  
Senbiao Xi ◽  
Yifeng Zhong ◽  
Zheng Shi ◽  
Qingshan Yi

To solve the microstructure-related complexity of a three-dimensional textile composite, a novel equivalent model was established based on the variational asymptotic method. The constitutive modeling of 3D unit cell within the plate was performed to obtain the equivalent stiffness, which can be inputted into the 2D equivalent model (2D-EPM) to perform the bending, free-vibration and buckling analysis. The correctness and effectiveness of the 2D-EPM was validated by comparing with the results from 3D FE model (3D-FEM) under various conditions. The influence of yarn width and spacing on the equivalent stiffness was also discussed. Finally, the effective performances of 3D textile composite plate and 2D plain-woven laminate with the same thickness and yarn content were compared. The results revealed that the bending, buckling and free-vibration behaviors predicted by 2D-EPM were in good agreement with 3D-FEM, and the local field distributions within the unit cell of 3D textile composite plate were well captured. Compared with the 2D plain-woven laminate, the displacement of 3D textile composite plate was relatively larger under the uniform load, which may due to the fact that the through-the-thickness constrains of the former are only dependent on the binder yarns, while the warp yarns and weft yarns of the latter are intertwined closely.


2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Zeeshan Saeed ◽  
Steven W. B. Klaassen ◽  
Christian M. Firrone ◽  
Teresa M. Berruti ◽  
Daniel J. Rixen

Abstract A joint between two components can be seen as a means to transmit dynamic information from one side to the other. To identify the joint, a reverse process called decoupling can be applied. This is not as straightforward as the coupling, especially when the substructures have three-dimensional characteristics, or sensor mounting effects are significant, or the interface degrees-of-freedom (DoF) are inaccessible for response measurement and excitation. Acquiring frequency response functions (FRFs) at the interface DoF, therefore, becomes challenging. Consequently, one has to consider hybrid or expansion methods that can expand the observed dynamics on accessible DoF to inaccessible DoF. In this work, we attempt to identify the joint dynamics using the system equivalent model mixing (SEMM) decoupling method with a virtual point description of the interface. Measurements are made only at the internal DoF of the uncoupled substructures and also of the coupled structure assuming that the joint dynamics are observable in the assembled state. Expanding them to the interface DoF and performing coupling and decoupling operations iteratively, the joint is identified. The substructures under consideration are a disk and blade—an academic test geometry that has a total of 18 blades but only one blade-to-disk joint is considered in this investigation. The joint is a typical dove-tail assembly. The method is shown to identify the joint without any direct interface DoF measurement.


1974 ◽  
Vol 14 (3) ◽  
pp. 118-122 ◽  
Author(s):  
L. S. Srinath ◽  
A. V. S. S. S. R. Sarma

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2381 ◽  
Author(s):  
Renxiu Han ◽  
Guoxi Li ◽  
Jingzhong Gong ◽  
Meng Zhang ◽  
Kai Zhang

In order to effectively improve the dynamic characteristics of the fixed metal joint interface, it is important to establish a correct equivalent model of the metal joint interface. In this paper, three equivalent methods for simulating the metal joint interface are analyzed, including the virtual material method, spring damping method, finite element method, and verification by modal experiment. First, according to the contact mechanics model of the constructed metal joint interface, the physical properties of the three-dimensional models of the fixed joint interface are assigned in the ANSYS software. Then, three methods are used for the modal analysis and compared with a modal experiment. The results show that the modal shapes of the three theoretical methods are consistent with those of the experimental modes. The first five natural frequencies obtained by the virtual material method are closest to the experimental natural frequencies, and the errors are within 10%. The errors of the other two methods are between 9% and 39%. Therefore, the virtual material method is a better equivalent method of the metal joint interface.


2020 ◽  
Vol 182 ◽  
pp. 02003
Author(s):  
Wenyuan Xian ◽  
Ran Ding ◽  
Ying Qiao ◽  
Zongxiang Lu ◽  
Shangqiang Li ◽  
...  

When the large-scale renewable power island is connected to VSC-HVDC transmission system, we should figure out the steady-state operation area of VSC-HVDC converter station. Based on the equivalent model of renewable energy island, the constraints of VSC-HVDC converter station are analyzed, and a fast method for calculating steady-state operation area of converter station is presented in this paper. The influence of equivalent line impedance of renewable energy island, transformer ratio of converter station and voltage setting value of grid-connected point on steady-state operation area of converter station is analyzed. And the three-dimensional view of the steady-state operation area of the converter station under different grid-connected voltage is depicted.


2005 ◽  
Vol 33 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Michaela Zorn-Kruppa ◽  
Svitlana Tykhonova ◽  
Gazanfer Belge ◽  
Jürgen Bednarz ◽  
Horst A. Diehl ◽  
...  

Within the last decade, extensive research in the field of tissue and organ engineering has focused on the development of in vitro models of the cornea. The use of organotypic, three-dimensional corneal equivalents has several advantages over simple monolayer cultures. The aim of this study was to develop a corneal equivalent model composed of the same cell types as in the natural human tissue, but by using immortalised cell lines to ensure reproducibility and to minimise product variation. We report our success in the establishment of an SV40-immortalised human corneal keratocyte cell line (designated HCK). A collagen matrix, built up with these cells, displayed the morphological characteristics of the human stromal tissue and served as a biomatrix for the immortalised human corneal epithelial and endothelial cells. Histological cross-sections of the whole-cornea equivalents resemble human corneas in tissue structure. This organotypic in vitro model may serve as a research tool for the ophthalmic science community, as well as a model system for testing for eye irritancy and drug efficacy.


2013 ◽  
Vol 353-356 ◽  
pp. 3304-3307
Author(s):  
Meng Yan Song ◽  
Ge Tian ◽  
Ming Wu Yuan ◽  
Li Na Ge ◽  
Jing Jing Song ◽  
...  

In this paper, the equivalent mechanical spring model of the three-dimensional continuum is studied. By using stiffness calculation formulas of three-dimensional continuum column under axial force and bending force, which are primary force states in the column, a mechanical equivalent trusses model with the same width and height is derived. The equivalent model is statically indeterminate trusses system of spring. The 3D spring calculation model can be used in the dynamic characteristic analysis. With the comparison of the first four order frequency values between the solid model and the equivalent spring model, it shows that the equivalent spring model not only have the equivalent stiffness in the static analysis but also have the equivalent dynamic characteristics in the dynamic analysis.


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