MATHEMATICAL MODEL OF MATERIALS OF STRUCTURES AND ELEMENTS OF RESTORED SOIL DAMS FOR NUMERICAL CALCULATIONS

2021 ◽  
pp. 46-51
Author(s):  
V. YA. ZHARNITSKIY ◽  
◽  
A. P. SMIRNOV
Keyword(s):  
Negative Impact ◽  
Emergency Situation ◽  
Numerical Calculations ◽  
Stress And Strain ◽  
Operational Parameters ◽  
Reliable Operation ◽  
Operational Factors ◽  
Materials Used ◽  
Technical Operation ◽  
Strain Tensors

Identified in the process of analyzing the operation of the structure, in the conditions of its operation, allow to assess the actual reserves of the bearing capacity of the structure and take effective measures to restore the operational parameters. The main criteria influencing the choice of mathematical models of materials for structures and elements of soil dams are more consistent with the model of the equation of state connecting the components of stress and strain tensors, as well as the rate of their change, which are obtained and tested for numerical calculations and have a full set of constants for materials used in the calculations of earth dams, the choice of their structures (concrete,reinforced concrete, soils, etc.). Reliable operation of soil dams is possible only if all proper conditions are met. The causes of dam accidents and their damage must be known not only to eliminate errors at the design and construction stages, but also during their operation. In order to exclude the negative impact of operational factors on the safety of soil HTS, it is necessary not only to strictly observe the rules of technical operation and take measures to exclude the possibility of an emergency situation during technological operations at facilities, but also to have methods for predictive justification of the restoration of strength and operational indicators of structures and elements of soil dams.

Linear elastic eigenstates of the compliance tensor for trigonal crystals

2000 ◽  
Vol 215 (1) ◽  
pp. 1-9 ◽  
Author(s):  
P.S. Theocaris ◽  
D.P. Sokolis
Keyword(s):  
Strain Energy ◽  
Elastic Strain Energy ◽  
Symmetric Tensor ◽  
Stress And Strain ◽  
Linear Elastic ◽  
Trigonal System ◽  
Compliance Tensor ◽  
Characteristic Values ◽  
Strain Tensors ◽  
Elastic Strain Energy Density

The spectral decomposition of the compliance fourth-rank tensor, representative of a trigonal crystalline or other anisotropic medium, is offered in this paper, and its characteristic values and idempotent fourth-rank tensors are established, with respect to the Cartesian tensor components. Consequently, it is proven that the idempotent tensors serve to analyse the second-rank symmetric tensor space into orthogonal subspaces, resolving the stress and strain tensors for the trigonal medium into their eigentensors, and, finally, decomposing the total elastic strain energy density into distinct, autonomous components. Finally, bounds on the values of the compliance tensor components for the trigonal system, dictated by the classical thermodynamical argument for the elastic potential to be positive definite, are estimated by imposing the characteristic values of the compliance tensor to be strictly positive.

scholarly journals PENGARUH PENYAMAKAN ZIRKONIUM TERHADAP UJI KEKUATAN TARIK, UJI KEKUATAN SOBEK, UJI KEMULURAN DAN UJI SUHU KERUT PADA BERBAGAI JENIS KULIT IKAN (The Effect of Zirconium Tanning Against Tensile Strength Test, Strength Test of Tear, Glide Test, and Wrinkle Temperature Test on Different Fish Types)

2018 ◽  
Vol 13 (2) ◽  
pp. 105
Author(s):  
Rokhmah Hergiyani ◽  
Y. S. Darmanto ◽  
Lukita Purnamayati
Keyword(s):  
Tensile Strength ◽  
Negative Impact ◽  
Strength Test ◽  
Collagen Fibers ◽  
Raw Material ◽  
Tear Strength ◽  
Complex Processes ◽  
Materials Used ◽  
The One ◽  
Physical Changes

Kulit ikan merupakan limbah perikanan yang dapat memberikan dampak negatif pada lingkungan. Salah satu cara untuk menanggulangi limbah tersebut adalah dengan proses penyamakan kulit. Penyamakan kulit adalah rangkaian proses yang sangat kompleks terjadi banyak perubahan fisik dan kimia di satu sisi, bagian yang tidak berguna dihilangkan dari kulit mentah untuk mendapatkan serat kolagen murni dan membuka struktur serat kolagen. Proses penyamakan yang tidak baik mengakibatkan kulit menjadi rusak, lemas, dan kebusukan, sehingga penanganannya dapat dengan cara menambah bahan penyamak untuk menguatkan dan menghindari kebusukan. Bahan penyamak yang digunakan yaitu zirconium. Tujuan penelitian ini adalah untuk mengetahui pengaruh penyamakan zirkonium terhadap uji kekuatan tarik, uji kekuatan sobek, uji kemuluran dan uji suhu kerut pada berbagai jenis ikan. Bahan baku yang digunakan adalah kulit ikan nila, kakap dan bandeng. Metode penelitian yang digunakan adalah experimental laboratories menggunakan Rancangan Acak Lengkap (RAL) dengan tiga kali ulangan dan  menggunakan analisa ragam ANOVA. Hasil uji menunjukan penggunaan zirkonium 7,5% terhadap kulit ikan nila, kakap, dan bandeng berpengaruh nyata (p<0,05) pada kekuatan tarik, kekuatan sobek, kemuluran dan suhu kerut pada karakteristik penyamakan. Penggunaan bahan penyamak zirkonium 7,5% terbaik dihasilkan oleh kulit ikan kakap pada uji kekuatan tarik 1675,84 N/cm2, kekuatan sobek 163,92 N/cm2 dan uji suhu kerut 103,45˚C sedangkan kemuluran untuk hasil terbaik pada kulit bandeng sebesar 28,74%, jadi setiap ikan mempunyai ciri kulit tersendiri pada setiap parameter uji. The skin of the fish waste is a fishery that can give a negative impact on the environment. One way of tackling the waste is by the process of tanning leather. Tanning is a very complex processes occur many chemical and physical changes on the one hand, the useless removed from rawhide to get pure collagen fibers and the open structure of the collagen fibers. The process of tanning is not a good result in the skin becomes broken, buckled, and corruption, so that responses can be with how to add ingredients to strengthen Tanner and avoid corruption. On the research of materials used i.e. Tanners used are zirconium.. The purpose of this research is to know the influence of zirconium tanning against test tensile strength, tear strength test, test and test temperature wrinkle elongation on various types of fish. The raw material used is leather fish tilapia, milkfish and snapper. Research methods used are experimental laboratories using Complete Random Design (RAL) with three-time repeats and a range of analysis using ANOVA. Test results showed the use of zirconium 7.5% against the skin of the fish, snapper, tilapia and milkfish influential real (p < 0.05) on the tensile strength, tear strength, elongation and wrinkle on temperature characteristics of tanning. The use of zirconium Tanner 7.5% best produced by skin test on a snapper 1675.84 tensile strength N/cm2, the strength of RIP 163.92 N/cm2 and test the temperature of the wrinkle 103,45 ˚ C while elongation for the best results on the skin of the banding of 28.74%, so each fish has its own skin characteristics on each test parameter.

scholarly journals Chemical Sand Consolidation: From Polymers to Nanoparticles

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1069 ◽  
Author(s):  
Fahd Saeed Alakbari ◽  
Mysara Eissa Mohyaldinn ◽  
Ali Samer Muhsan ◽  
Nurul Hasan ◽  
Tarek Ganat
Keyword(s):  
Compressive Strength ◽  
Negative Impact ◽  
Production Performance ◽  
Polymer Materials ◽  
Rock Permeability ◽  
Sand Control ◽  
Materials Used ◽  
The Impact ◽  
Chemical Material ◽  
Chemical Materials

The chemical sand consolidation methods involve pumping of chemical materials, like furan resin and silicate non-polymer materials into unconsolidated sandstone formations, in order to minimize sand production with the fluids produced from the hydrocarbon reservoirs. The injected chemical material, predominantly polymer, bonds sand grains together, lead to higher compressive strength of the rock. Hence, less amounts of sand particles are entrained in the produced fluids. However, the effect of this bonding may impose a negative impact on the formation productivity due to the reduction in rock permeability. Therefore, it is always essential to select a chemical material that can provide the highest possible compressive strength with minimum permeability reduction. This review article discusses the chemical materials used for sand consolidation and presents an in-depth evaluation between these materials to serve as a screening tool that can assist in the selection of chemical sand consolidation material, which in turn, helps optimize the sand control performance. The review paper also highlights the progressive improvement in chemical sand consolidation methods, from using different types of polymers to nanoparticles utilization, as well as track the impact of the improvement in sand consolidation efficiency and production performance. Based on this review, the nanoparticle-related martials are highly recommended to be applied as sand consolidation agents, due to their ability to generate acceptable rock strength with insignificant reduction in rock permeability.

Microplane Model for Fracturing Damage of Triaxially Braided Fiber-Polymer Composites

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Ferhun C. Caner ◽  
Zdeněk P. Bažant ◽  
Christian G. Hoover ◽  
Anthony M. Waas ◽  
Khaled W. Shahwan
Keyword(s):  
Present Model ◽  
Material Model ◽  
Multiscale Model ◽  
Stress And Strain ◽  
Band Model ◽  
Braided Composites ◽  
Microplane Model ◽  
Explicit Finite Element ◽  
Crack Band ◽  
Strain Tensors

A material model for the fracturing behavior for braided composites is developed and implemented in a material subroutine for use in the commercial explicit finite element code ABAQUS. The subroutine is based on the microplane model in which the constitutive behavior is defined not in terms of stress and strain tensors and their invariants but in terms of stress and strain vectors in the material mesostructure called the “microplanes.” This is a semi-multiscale model, which captures the interactions between inelastic phenomena such as cracking, splitting, and frictional slipping occurring on planes of various orientations though not the interactions at a distance. To avoid spurious mesh sensitivity due to softening, the crack band model is adopted. Its band width, related to the material characteristic length, serves as the localization limiter. It is shown that the model can realistically predict the orthotropic elastic constants and the strength limits. More importantly, the present model can also fit the tests of size effect on the strength of notched specimens and the post-peak behavior, which have been conducted for this purpose. When used in the ABAQUS software, the model gives a realistic picture of the axial crushing of a braided tube by a divergent plug.

Study on Micro Milling Tool with Hot-Pressed Sintered Ti(C7N3)-Based Cermet

2016 ◽  
Vol 693 ◽  
pp. 906-913
Author(s):  
Kai Tao Xu ◽  
Bin Zou ◽  
Chuan Zhen Huang ◽  
Hui Jun Zhou ◽  
Han Lian Liu ◽  
...  
Keyword(s):  
Static Load ◽  
Electrical Discharge Machining ◽  
Negative Impact ◽  
Micro Milling ◽  
Stress And Strain ◽  
End Mill ◽  
Milling Performance ◽  
Milling Tool ◽  
Minimum Stress ◽  
Milling Tools

Micro milling is most flexible to create 3D features for application. However, how to design and fabrication of high precision micro milling tools are one of big challenges for mechanical micro milling. Commercially available micro milling tools are usually simply made from downsizing of macro milling tools, which have negative impact on milling performance. Therefore, in this paper, firstly, various structural of micro milling tools were optimized with abaqus that investigated stress and strain under certain static load on the cutting edges. Then, results showed the minimum stress and strain was a micro hexagonal end mill. Finally, a Ti (C7N3) cermet micro hexagonal end mill with a radius of 0.5mm was fabricated by wire electrical discharge machining, and the evaluation experiments for the hexagonal mill have been processed on a micro milling centre.

scholarly journals The method for determining working resistance of advance support bracket in deep fully mechanized roadway based on Flac3D

2018 ◽  
Vol 10 (6) ◽  
pp. 168781401878362 ◽  
Author(s):  
Guanghui Xue ◽  
Jijie Cheng ◽  
Jian Guan ◽  
Jingxuan Chai ◽  
Guofeng Zhang ◽  
...  
Keyword(s):  
Coupling Model ◽  
Surrounding Rock ◽  
Numerical Calculations ◽  
Stress And Strain ◽  
Determination Method ◽  
Mechanical Coupling ◽  
Mining Depth ◽  
Geological Conditions ◽  
Working Principle ◽  
Working Resistance

Fully mechanized roadway is an area of high accident incidence, and the problem is more prominent with the increase of mining depth of coal resources. The advance support scheme put forward for fully mechanized mining roadway with self-moving support and anchor combined unit, and the configuration and working principle of support robot was explicated. A determination method on the working resistance of advance support bracket was proposed based on mechanical coupling model of surrounding rock-advance support brackets. Taking the geological conditions of the Qishan mine as an example, the process of analyzing and determining the working resistance of the advance support bracket was described using this method. An advance support bracket was designed using SolidWorks, and the working load was obtained based on numerical calculations. Then the stress and strain were analyzed using ANSYS. The results showed that the designed advance support bracket can withstand the corresponding top plate pressure. It provides a new method and thought for study and development of advance supporting equipment in deep fully mechanized roadway.

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