Strength and Deformability of Hollow Thin-Walled Mini-Spheres

2021 ◽  
Vol 320 ◽  
pp. 3-7
Author(s):  
Viktor Mironov ◽  
Ervins Blumbergs ◽  
Alexey Tatarinov ◽  
Kaspars Kalnins
Keyword(s):  
Heat Transfer ◽  
Mechanical Properties ◽  
Sound Pressure ◽  
Physical And Mechanical Properties ◽  
Wall Material ◽  
Mechanical Vibrations ◽  
Pressure Pulses ◽  
Thin Walled

Thin-walled hollow mini-spheres several millimeters in diameter have promising applications as components for the absorption of sound, pressure pulses and mechanical vibrations, as well as heat transfer elements. In this paper, an assessment of some physical and mechanical properties, including the strength and elasticity of metallic mini spheres, is given. To a great extent, the properties are determined by the wall material, however, can be modified by the coating as well.

scholarly journals Physical and mechanical properties of composites based on hemp shives and lime

2018 ◽  
Vol 49 ◽  
pp. 00010 ◽  
Author(s):  
Przemysław Brzyski ◽  
Grzegorz Łagód
Keyword(s):  
Mechanical Properties ◽  
Thermal Insulation ◽  
Thermal Conductivity Coefficient ◽  
Positive Impact ◽  
Physical And Mechanical Properties ◽  
Wall Material ◽  
High Porosity ◽  
Plant Origin ◽  
Timber Frame ◽  
Properties Of Composites

One of the objectives of sustainable development in construction is the use of low-processed materials. They have a positive impact on the ecological balance of the building throughout the entire life cycle. Examples of such materials are materials of plant origin - straw, shives, cellulose fibers. They are used as thermal insulation or wall material. In recent years, hemp shives are increasingly used as a component of a lime-based composite, which performs the function of wall filling in timber frame constructions. The shives, due to the high porosity, determine the high thermal insulation properties of the composite. The physico-mechanical properties of the composite can be modified depending on various factors, including the ratio of hemp shives to the binder. The lime binder, in turn, can be modified by hydraulic and pozzolan additives. The paper presents mechanical properties (compressive and flexural strength) as well as physical properties (density, porosity, thermal conductivity coefficient, absorbability) of composites with various proportions of hemp shives of the Bialobrzeskie variety to the lime binder modified with Portland cement and metakaolinite.

MECHANICAL AND THERMAL PROPERTIES OF SAWDUST CONCRETE

2017 ◽  
Vol 79 (6) ◽  
Author(s):  
Ruhal Pervez Memon ◽  
Abdul Rahman Mohd. Sam ◽  
A. S. M. Abdul Awal ◽  
Lemar Achekzai
Keyword(s):  
Heat Transfer ◽  
Mechanical Properties ◽  
Tensile Strength ◽  
Thermal Properties ◽  
Lightweight Concrete ◽  
Physical And Mechanical Properties ◽  
Developing Nations ◽  
Mechanical And Thermal Properties ◽  
Construction Technology ◽  
Long Duration

 Industrialization in developing countries has resulted in an increase in agricultural output and consequent accumulation of unmanageable agro wastes. Pollution arising from such wastes is a matter of concern for many developing nations. The aim of this study is to investigate the behavior of lightweight concrete and the utilization of sawdust as waste material in concrete. This paper focuses on the manufacturing of concrete which possess long duration heat transfer by using sawdust waste. In this research, cement to sawdust ratio of 1:1, 1:2 and 1:3 by volume was prepared for sawdust concrete, and the ratio of sand was kept constant that is 1. At these ratios, the mechanical and thermal properties like density, workability, strength and heat transfer were measured after, 7, 28 and 56 days of air curing. The tests results show that with the increase in the amount of sawdust, the workability, compressive strength, tensile strength and flexural strength decreased. It also resulted in reduction of heat transfer of sawdust concrete. Taking into account the overall physical and mechanical properties, sawdust concrete can be used in construction technology. 

scholarly journals Investigation of the frequency of free vibrations for pipelines with different physical and mechanical properties of the material

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Andrey Dmitriev
Keyword(s):  
Mechanical Properties ◽  
Large Diameter ◽  
Physical And Mechanical Properties ◽  
External Pressure ◽  
Pipe Length ◽  
Shell Form ◽  
Underground Pipelines ◽  
Elastic Resistance ◽  
Ground Conditions ◽  
Thin Walled

This paper raises the question of a new approach to the dynamic calculation of thin-walled underground pipelines of large diameter, which is based on the application of the Vlasov-Novozhilov half-time theory of medium-bend shells, which ignores the M1 moments that bend the cylindrical shell in the longitudinal direction, since they are much smaller than the M2 moments that bend it in the transverse direction. The resolving equation for this approach is a homogeneous 4th-order differential equation that uses two boundary conditions at each end to solve it. The resulting equation takes into account the parameter of the longitudinal force, the value of the internal pressure, the coefficient of elastic resistance of the soil, the parameter of thinness, as well as the attached mass of the soil. Based on the data obtained from the derived formulas, the frequency characteristics of thin-walled underground pipelines of large diameter with different physical and mechanical properties are determined depending on the length of the element, as well as ground conditions. It is established that the minimum frequencies for the shell form of vibrations in various ground conditions are realized only for steel pipes, and for polyethylene and fiberglass pipes, depending on the coefficient of elastic resistance of the soil, they can be realized both in the rod and shell form. At the same time, using a dynamic stability criterion, derived expressions to determine the critical external pressure, taking into account the pipe length and the number of half waves in the cross section in which there is a constructive denial of the pipeline. Based on this expression, a formula for determining the critical depth of laying for thin-walled pipelines is obtained.

scholarly journals Heat transfer and physical-mechanical properties analysis of particleboard produced with ZnO nanoparticles addition

BioResources ◽  
2019 ◽  
Vol 14 (4) ◽  
pp. 9904-9915 ◽  
Author(s):  
Luana Cristal Lirya Silva ◽  
Felipe Oliveira Lima ◽  
Eduardo Chahud ◽  
André L. Christoforo ◽  
Francisco A. Rocco Lahr ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Mechanical Properties ◽  
Transfer Process ◽  
Zno Nanoparticles ◽  
Physical And Mechanical Properties ◽  
Heat Transfer Process ◽  
Heat Distribution ◽  
European Standard ◽  
Metallic Oxide ◽  
Brazilian Standard

The use of particleboards (PB) has increased quickly as an alternative engineered wood product mainly due to its having a better ratio of resistance to weight and more elimination of wood defects, such as the presence of knots. Although the panel industry has been constantly growing, innovations are still necessary to improve the final product. The use of metallic oxide nanoparticles on the wood-based panels has the potential to increase the heat transfer process and improve the physico-mechanical properties. The aim of this work was to evaluate the influence of the addition of zinc oxide (ZnO) nanoparticles in PB, correlating the physical and mechanical properties of the panel with the heat transfer process at 180 °C. The results were compared with the Brazilian standard ABNT NBR 14810-2 (2013) and the European standard EN 312 (2010), as well with works found in literature. The results showed a homogenous heat distribution during the pressing, which improved physical properties, decreasing the 24h swelling from 22.2% to 14.9% and the 24 h absorption from 30.29% to 21.0%. Besides that, MOR values was increased from 11.3 MPa to 14.5 MPa and the MOE from 1880 MPa to 2510 MPa.

THE INFLUENCE OF HEAT TRANSFER ON PHYSICAL AND MECHANICAL PROPERTIES IN NONCONVENTIONAL PROCESSES OF METALLIC SOLIDS PLASTIC DEFORMATION

2002 ◽  
Vol 16 (04) ◽  
pp. 135-141
Author(s):  
MARIANA POP ◽  
TRAIAN CANTA ◽  
AUREL POP
Keyword(s):  
Heat Transfer ◽  
Mechanical Properties ◽  
Mathematical Model ◽  
Plastic Deformation ◽  
Cross Sections ◽  
Physical And Mechanical Properties ◽  
Variable Cross ◽  
Drawing Process ◽  
Dieless Drawing ◽  
Temperature Strain

The aim of this paper is to present a mathematical model for the steady state of the dieless drawing process. With this model, it is possible to study the influence of various process parameters, such as temperature, strain, strain rate and stress. The paper also presents some elements of the process control for producing variable cross-sections (cone-contour and sinus-contour).

PEMANFAATAN KAYU AKASIA MANGIUM (Acacia mangium Willd) UNTUK MEBEL

2012 ◽  
Vol 4 (1) ◽  
pp. 1
Author(s):  
Djoko Purwanto
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Physical Properties ◽  
Treatment Process ◽  
Acacia Mangium ◽  
Physical And Mechanical Properties ◽  
Wood Fibers ◽  
Test Parameters ◽  
Mechanical And Physical Properties ◽  
Scale Scores

Timber Acacia mangium (Acacia mangium, Willd) for Furniture. The study aims to determine the mechanical and physical properties and the decorative value (color and fiber) wood of acacia mangium with using finishing materials. This type of finishing material used is ultran lasur natural dof ,ultran lasur classic teak, aqua politur clear dof, aqua politur akasia dan aqua politur cherry. After finishing the wood is stored for 3 months. Test parameters were observed, namely, physical and mechanical properties of wood, adhesion of finishing materials, color and appearance of the fiber, and timber dimensions expansion. The results showed that the mechanical physical properties of acacia wood qualified SNI. 01-0608-89 about the physical and mechanical properties of wood for furniture, air dry the moisture content from 13.78 to 14.89%, flexural strength from 509.25 to 680.50 kg/cm2, and compressive strength parallel to fiber 342.1 - 412.9 kg/cm2. Finishing the treatment process using five types of finishing materials can increase the decorative value (color and fiber) wood. Before finishing the process of acacia mangium wood has the appearance of colors and fibers and less attractive (scale scores 2-3), after finishing acacia wood fibers have the appearance of colors and interesting and very interesting (scale 4-5).Keywords: mangium wood, mechanical properties, decorative value, finishing, furniture.

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