scholarly journals Mechanical Properties Research on Suspended-dome Structure with Discontinuous Support Under Different Parameters

2017 ◽  
Vol 11 (1) ◽  
pp. 303-314
Author(s):  
Yu Jinghai ◽  
Leng Ming ◽  
Zhang Zhongyu ◽  
Jiang Zhiyu ◽  
Wang Zhengkai
Keyword(s):  
Mechanical Properties ◽  
Parametric Analysis ◽  
Structural Parameters ◽  
Supporting System ◽  
Vertical Stiffness ◽  
Stiffness Constant ◽  
Support Reaction ◽  
Steel Consumption ◽  
Dome Structure ◽  
Scope Of Application

Introduction: For suspended-dome with big partial hole, two kinds of feasible plans were proposed. Method: One of the plans was to adjust suspended-dome’s members, and another to build auxiliary supporting system to support the suspended-dome with columns together. These kinds of suspended-dome’s main structural parameters include stiffness, member force, steel consumption, support reaction and stability, and parametric analysis is based on these parameters. Conclusion: Firstly,the scope of application was illustrated for the former plan. Then, an equivalent vertical stiffness algorithm was put forward for the latter plan. In the latter plan, limit stiffness constant was introduced to quantify the method for solving discontinuous support problem.

Changes of Selected Structural and Mechanical Properties of the Strzelin Granites As Induced By Thermal Loads / Wpływ Obciążeń Termicznych Na Zmiany Niektórych Strukturalnych I Mechanicznych Właściwości Granitów Strzelińskich

2012 ◽  
Vol 57 (4) ◽  
pp. 951-974 ◽  
Author(s):  
Andrzej Nowakowski ◽  
Mariusz Młynarczuk
Keyword(s):  
Mechanical Properties ◽  
Nuclear Waste ◽  
Structural Changes ◽  
Structural Parameters ◽  
Total Porosity ◽  
Fracture Network ◽  
Qualitative Description ◽  
Temperature Changes ◽  
Heating And Cooling ◽  
Waste Repositories

Abstract Temperature is one of the basic factors influencing physical and structural properties of rocks. A quantitative and qualitative description of this influence becomes essential in underground construction and, in particular, in the construction of various underground storage facilities, including nuclear waste repositories. The present paper discusses the effects of temperature changes on selected mechanical and structural parameters of the Strzelin granites. Its authors focused on analyzing the changes of granite properties that accompany rapid temperature changes, for temperatures lower than 573ºC, which is the value at which the β - α phase transition in quartz occurs. Some of the criteria for selecting the temperature range were the results of measurements carried out at nuclear waste repositories. It was demonstrated that, as a result of the adopted procedure of heating and cooling of samples, the examined rock starts to reveal measurable structural changes, which, in turn, induces vital changes of its selected mechanical properties. In particular, it was shown that one of the quantities describing the structure of the rock - namely, the fracture network - grew significantly. As a consequence, vital changes could be observed in the following physical quantities characterizing the rock: primary wave velocity (vp), permeability coefficient (k), total porosity (n) and fracture porosity (η), limit of compressive strength (Rσ1) and the accompanying deformation (Rε1), Young’s modulus (E), and Poisson’s ratio (ν).

scholarly journals Gender Difference in Architectural and Mechanical Properties of Medial Gastrocnemius–Achilles Tendon Unit In Vivo

Life ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 569
Author(s):  
Liqin Deng ◽  
Xini Zhang ◽  
Songlin Xiao ◽  
Baofeng Wang ◽  
Weijie Fu
Keyword(s):  
Mechanical Properties ◽  
Gender Differences ◽  
Gender Difference ◽  
Achilles Tendon ◽  
Medial Gastrocnemius ◽  
Regular Exercise ◽  
Training Experience ◽  
Exercise Habits ◽  
Vertical Stiffness

This study aims to explore whether gender differences exist in the architectural and mechanical properties of the medial gastrocnemius–Achilles tendon unit (gMTU) in vivo. Thirty-six healthy male and female adults without training experience and regular exercise habits were recruited. The architectural and mechanical properties of the gMTU were measured via an ultrasonography system and MyotonPRO, respectively. Independent t-tests were utilized to quantify the gender difference in the architectural and mechanical properties of the gMTU. In terms of architectural properties, the medial gastrocnemius (MG)’s pennation angle and thickness were greater in males than in females, whereas no substantial gender difference was observed in the MG’s fascicle length; the males possessed Achilles tendons (ATs) with a longer length and a greater cross-sectional area than females. In terms of mechanical properties, the MG’s vertical stiffness was lower and the MG’s logarithmic decrement was greater in females than in males. Both genders had no remarkable difference in the AT’s vertical stiffness and logarithmic decrement. Gender differences of individuals without training experience and regular exercise habits exist in the architectural and mechanical properties of the gMTU in vivo. The MG’s force-producing capacities, ankle torque, mechanical efficiency and peak power were higher in males than in females. The load-resisting capacities of AT were greater and the MG strain was lesser in males than in females. These findings suggest that males have better physical fitness, speed and performance in power-based sports events than females from the perspective of morphology and biomechanics.

The Dynamic Characteristics of Rigid Frame Single-Rib Arch Bridge

2013 ◽  
Vol 368-370 ◽  
pp. 1426-1430
Author(s):  
Li Xiong Gu ◽  
Rong Hui Wang
Keyword(s):  
Dynamic Characteristics ◽  
Bending Strength ◽  
Dynamic Properties ◽  
Structural Parameters ◽  
Bending Stiffness ◽  
Torsional Stiffness ◽  
Lateral Stiffness ◽  
Arch Bridge ◽  
Vertical Stiffness ◽  
Rigid Frame

In this paper, by establishing the finite element model to study the dynamic characteristics of rigid frame single-rib arch bridge. By respectively changing structural parameters of the span ratios, and the compressive stiffness of arch, and the bending stiffness of arch, and the bending stiffness of bridge girder, and the layout of boom to find out the regularity of the structure on lateral stiffness, and vertical stiffness, and torsional stiffness as well as dynamic properties, it come out the results of that lateral stiffness of the structure is weaker, and increasing the span ratios and the compressive strength of arch are conducive to the improvement of the overall stiffness, and improving the bending strength of arch and layout of boom are less effect on the overall stiffness and mode shape.

scholarly journals MACHINABILITY ANALYSIS OF AN AL-1,2% Pb ALLOY SOLIDIFIED IN A HORIZONTAL DIRECTIONAL DEVICE

2019 ◽  
Vol 16 (31) ◽  
pp. 860-874
Author(s):  
Jacson Malcher NASCIMENTO ◽  
Regiane Socorro BARROS ◽  
Camila Yuri KONNO ◽  
Adrina Paixão SILVA ◽  
Otávio ROCHA ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tool Wear ◽  
Tribological Behavior ◽  
Structural Parameters ◽  
Cutting Temperature ◽  
Industrial Processes ◽  
Unsteady State ◽  
Flow Conditions ◽  
Monotectic Alloy ◽  
Machinability Analysis

In general, the binary monotectic alloys are characterized by the limited solubility in the liquid state, which gives them a benefited tribological behavior such as wear resistance. Researches regarding the development of monotectic alloy microstructures during the unsteady-state heat flow conditions are fundamental, as it encompasses most of the solidification industrial processes. However, the microstructural relationship between the mechanical properties of monotectic alloys is little explored and practically nil. In this context, the present study consists of investigating and correlating solidification thermal variables and structural parameters such as microhardness and machinability (cutting temperatures and tool wear) of Al-1.2wt% Pb alloy, in a horizontal directional device. It was observed that the cutting temperature and tool wear results complement each other when correlated with position and interphase spacing, indicating that for smaller interphase spacings the addition of lead harms machinability.

scholarly journals Physico-Mechanical Performance Evaluation of Large Pore Synthetic Meshes with Different Textile Structures for Hernia Repair Applications

2018 ◽  
Vol 26 (2(128)) ◽  
pp. 79-86 ◽  
Author(s):  
Pengbi Liu ◽  
Hong Shao ◽  
Nanliang Chen ◽  
Nanliang Cheng ◽  
Jinhua Jiang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Hernia Repair ◽  
Mechanical Performance ◽  
Structural Parameters ◽  
Strength Properties ◽  
Open Loop ◽  
Burst Strength ◽  
Patch Application ◽  
Large Pore ◽  
Polypropylene Monofilament

This paper studied the relationship between the textile structure of warp knitted hernia repair meshes and their physico-mechanical properties to solve the problem of hernia patch application evaluation and clear the mechanism of hernia patch structure-performance for clinical application. Six different prototypes of large pore meshes were fabricated, including four kinds of meshes with different pore shapes: H (hexagonal), D (diamond), R (round) and P (pentagonal); and two kinds of meshes with inlays: HL (hexagonal with inlays) and DL (diamond with inlays), using the same medical grade polypropylene monofilament. All meshes were designed with the same walewise density and coursewise density. Then the influence of other structural parameters on the physico-mechanical properties of the meshes was analysed. The physico-mechanical properties of these meshes tested meet the requirements of hernia repair, except mesh DL, whose tear resistance strength (12.93 ± 2.44 N in the transverse direction) was not enough. Mesh R and P demonstrated less anisotropy, and they exhibited similar physico-mechanical properties. These four kinds of meshes without inlays demonstrated similar ball burst strength properties, but mesh HL and DL exhibited better ball burst strength than the others. All in all, uniform structures are expected to result in less anisotropy, and meshes with inlays, to some extent, possess higher mechanical properties. And the ratio of open loop number to closed loop number in a repetition of weave of fabric has marked effect on the physico-mechanical properties. Thus we can meet the demands of specific patients and particular repair sites by designing various meshes with appropriate textile structures.

scholarly journals Experimental and FEM Research on Airport Cement Concrete Direct-Thickening Double-Deck Pavement Slabs under Aircraft Single-Wheel Dynamic Loads

2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Qingkun Yu ◽  
Liangcai Cai ◽  
Jianwu Wang
Keyword(s):  
Mechanical Properties ◽  
Structural Parameters ◽  
Element Model ◽  
Tension Stress ◽  
Cement Concrete ◽  
Wheel Load ◽  
Critical Position ◽  
Ansys Simulation ◽  
Longitudinal Edge ◽  
Airport Runway

The wide-use airport cement concrete direct-thickening double-deck pavement slabs (ACCDDPS) were selected as the research object to study their mechanical properties. The airport runway simulation test station (ARSTS) was used to conduct indoor tests to demonstrate the distribution of tension stress at the bottom of slabs and slabs deflection. Furthermore, ANSYS software was applied to establish finite element model (FEM) of ACCDDPS and analyze the mechanical laws under different loads. The indoor tests results are in good agreement with the ANSYS simulation results, and some consistent conclusions can be obtained that the maximum tension stress increases with wheel load, and the slab middle of the longitudinal edge is a critical position. In addition, we studied the influence of covered layer thickness, elastic modulus, and slab size on pavement slab mechanical properties by ANSYS, and we concluded that although the structural parameters are different, the critical position of ACCDDPS is still in the middle of the longitudinal edge. However, for the covered layer and the original surface layer, the law that the tension stress values vary with the structural parameters is different, but the maximum deflection value is about 0.1.

Conceptual Approach to Development, Structure Formation and Hardening Micro-Alloyed by Steels for the Metallurgical Tool

2020 ◽  
Vol 299 ◽  
pp. 658-663
Author(s):  
S.E. Krylova ◽  
Sergey V. Gladkovskii ◽  
E.V. Romashkov
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Chemical Composition ◽  
Structure Formation ◽  
Structural Parameters ◽  
Structural Transformations ◽  
Conceptual Approach ◽  
Phase And Structural Transformations ◽  
Technological Cycle ◽  
Development Structure

The scientific bases for the development of rational compositions and methods for hardening a large-sized metallurgical tool from micro-alloyed steels are stated. Based on the generalization of the experimental data, the regularities of phase and structural transformations at various stages of the technological cycle are revealed; the relationships between structural parameters, chemical composition and mechanical properties have been studied and described.

Analysis of the Fire-Resistance of Suspen Dome Structure

2012 ◽  
Vol 166-169 ◽  
pp. 1040-1044 ◽  
Author(s):  
Zhong Ling Zong ◽  
Yong Fu He ◽  
Shi Ge Li
Keyword(s):  
Mechanical Properties ◽  
Work Performance ◽  
Test Results ◽  
Analysis Method ◽  
Steel Cable ◽  
Mechanics Model ◽  
Time Integral ◽  
Integral Effect ◽  
Dome Structure ◽  
Temperature Test

Based on the mechanical properties of steel cable under the high temperature test results, the mechanical properties, such as yield strength, modulus of elasticity of steel cable and its mechanics model were obtained. Nonlinear numerical analysis method was established based on the time integral effect. Through the analysis of the suspen-dome structure, this paper discusses the characteristics of temperature field distribution, displacement and stress. The results show that: suspen-dome structure has better spatial work performance; the weak area of the structure is at the central, the main reason of large deformation is the reduction of stiffness and strength.

Additive manufacturing and mechanical properties of lattice-curved structures

2019 ◽  
Vol 25 (5) ◽  
pp. 895-903 ◽  
Author(s):  
Enrique Cuan-Urquizo ◽  
Mario Martínez-Magallanes ◽  
Saúl E. Crespo-Sánchez ◽  
Alfonso Gómez-Espinosa ◽  
Oscar Olvera-Silva ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fused Deposition Modeling ◽  
Structural Parameters ◽  
Structural Response ◽  
Layered Structures ◽  
Lattice Structures ◽  
Structure Property ◽  
Content Type ◽  
Fused Deposition ◽  
Curved Structures

Purpose The purpose of this paper is to study the feasibility of the fabrication of circle arc curved-layered structures via conventional fused deposition modeling (FDM) with three-axis machines and to identify the main structural parameters that have an influence on their mechanical properties. Design/methodology/approach Customized G-codes were generated via a script developed in MATLAB. The G-codes contain nozzle trajectories with displacements in the three axes simultaneously. Using these, the samples were fabricated with different porosities, and their influence on the mechanical responses evaluated via tensile testing. The load-displacement curves were analyzed to understand the structure-property relationship. Findings Circled arc curved-layered structures were successfully fabricated with conventional three-axis FDM machines. The response of these curved lattice structures under tensile loads was mapped to three main stages and deformation mechanisms, namely, straightening, stretching and fracture. The micro-structure formed by the transverse filaments affect the first stage significantly and the other two minimally. The main parameters that affect the structural response were found to be the transverse filaments, as these could behave as hinges, allowing the slide/rotation of adjacent layers and making the structure more shear sensitive. Research limitations/implications This paper was restricted to arc-curved samples fabricated with conventional three-axis FDM machines. Originality/value The FDM fabrication of curved-structures with controlled porosity and their relation to the resulting mechanical properties is presented here for the first time. The study of curved-lattice structures is of great relevance in various areas, such as biomedical, architecture and aerospace.

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