THE EQUIPMENT FOR DEFINITION OF PHYSICOMECHANICAL CHARACTERISTICS OF MATERIALS BY PRESS-IN METHOD (review)

2021 ◽  
pp. 107-124
Author(s):  
E.I. Oreshko ◽  
◽  
V.S. Erasov ◽  
D.A. Utkin ◽  
Ya.V. Avtayeva ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Computational Methods ◽  
Mechanical Characteristics ◽  
Element Model ◽  
Physicomechanical Characteristics ◽  
Definition Of ◽  
Hardness Values

The article considers the main methods for determining the hardness of materials. The basic formulas for calculating the mechanical characteristics of materials by hardness values are presented. The analysis of methods for calculating tensile diagrams of materials by indentation diagrams is carried out. The paper considers the approaches to building a finite element model of material indentation The need to improve existing standards and develop computational methods is shown with a detailed description of techniques for recalculating indentation diagrams into mechanical characteristics of materials.

METHODS FOR DETERMINING THE MECHANICAL CHARACTERISTICS OF MATERIALS USING INDENTATION (review)

2021 ◽  
pp. 104-118
Author(s):  
E.I. Oreshko ◽  
◽  
V.S. Erasov ◽  
N.O. Yakovlev ◽  
D.A. Utkin ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Computational Methods ◽  
Mechanical Characteristics ◽  
Element Model ◽  
Hardness Values

The paper considers the main methods for determining the hardness of materials. The basic formulas for calculating the mechanical characteristics of materials by hardness values are presented. The analysis of methods for calculating tensile diagrams of materials by indentation diagrams is carried out. Approaches to building a finite element model of material indentation are considered. The paper shows the need to improve existing standards and develop computational methods with a detailed description of techniques for recalculating indentation diagrams into mechanical characteristics of materials.

Shock environment design for space equipment testing

2016 ◽  
Vol 231 (6) ◽  
pp. 1154-1167 ◽  
Author(s):  
OMF Morais ◽  
CMA Vasques
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Test System ◽  
Test Apparatus ◽  
Shock Test ◽  
Shock Testing ◽  
Test Parameters ◽  
Shock Environment ◽  
Definition Of

The main specification in the verification by testing of space hardware vulnerability to shock excitations is the shock response spectrum. Although it compiles the most relevant information needed to describe the overall shock environment characteristics, shock testing still poses various difficulties and uncertainties concerning the suitability and operation of the shock test system used, and the adequate definition of the underlying test parameters. The approach followed from the interpretation of typical shock testing specifications to the development, validation, and characterization of the developed shock test system, including the definition and design of the relevant parameters influencing the attained shock environment, is described in this paper. The shock testing method here presented consists of a pendular in-plane resonant mono-plate shock test apparatus where the structural response of the ringing plate depends upon well-defined controllable parameters (e.g. impact velocity, striker shape, mass, and contact stiffness), which are parametrically determined to achieve the target shock environment specification. The concept and analytical model of two impacting bodies are used in a preliminary analysis to perform a rigid body motion analysis and contact assessment. A detailed finite element model is developed for the definition of the ringing plate dimensions, analysis of the plate dynamics and virtual shock testing. The assembled experimental apparatus is described and a test campaign is undertaken in order to properly characterize and assess the design and test parameters of the system. The developed shock test apparatus and corresponding finite element model are experimentally verified and validated. As a result of this study, a reliable finite element modeling methodology available for future shock test simulation and prediction of the experimental results was created, being an important tool for the adjustment of the shock test input parameters for future works. The developed shock test system was well characterized and is readily available to be used for shock testing of space equipment with varying specifications.

FINITE ELEMENT ANALYSIS OF THE MECHANICAL CHARACTERISTICS OF GLAUCOMA

2016 ◽  
Vol 16 (04) ◽  
pp. 1650060 ◽  
Author(s):  
PEISHAN DAI ◽  
HAN HAN ◽  
YALI ZHAO ◽  
MIN FAN
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Optic Nerve ◽  
Finite Element Model ◽  
Mechanical Characteristics ◽  
Element Model ◽  
Finite Element Method Result ◽  
Element Analysis ◽  
Human Eye ◽  
Geometry Model

Purpose: Construct a finite element model of the human eye to quantitatively analyze the mechanical characteristics of the human eye, especially the glaucoma damage process of the optic nerve head (ONH). Method: First, the geometry model of the human eye with nonuniform thickness was established based on a reasonable hypothesis and assumptions. Because the ONH is an important factor for glaucoma, we refine the structure of the ONH with lamina cribrosa. Then, mesh division was applied for finite element analysis. To simplify the complexity of the analysis, the materials of the model were assumed to be isotropic linear elastic materials, and physical properties such as Young’s modulus and Poisson’s ratio were set according to published literature. Next, proper constraints and loads were applied to the model and solved with a finite element method. Result: A finite element model of the human eye was created to simulate the mechanical characteristics of the eye structures under high intraocular pressure (IOP). The ONH depressed 1.057[Formula: see text]mm under 0.009[Formula: see text]MPa pressure to simulate high IOP. Conclusion: The constructed model is able to quantitatively simulate excavation of the optic disc and damage of the optic nerve. The result proved Houcheng Liang’s hypothesis about the ONH damage mechanism in glaucoma.

Effects of missing fasteners on the mechanical behavior of double-lap, multi-row composite bolted joints

2018 ◽  
Vol 52 (28) ◽  
pp. 3919-3933
Author(s):  
Fujian Zhuang ◽  
Puhui Chen
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Load Distribution ◽  
Mechanical Characteristics ◽  
Joint Stiffness ◽  
Element Model ◽  
Bolted Joints ◽  
Explicit Finite Element ◽  
Single Column ◽  
Failure Loads

This paper presents a numerical investigation into the effects of missing fasteners on the mechanical characteristics of double-lap, multi-row composite bolted joints. A highly efficient explicit finite element model, which was validated effective and accurate by experiments, was developed and employed to conduct the virtual tests. Single-column and multi-column joints with various positions of missing fastener were considered. It is shown that the removal of fasteners can reduce the joint stiffness significantly, especially in joints with fewer columns or missing fasteners in the outside rows. The removal of fasteners can also cause considerable reductions in both the initial significant failure loads and ultimate loads of multi-column joints, while in single-column joints only the initial significant failure loads are influenced. Considering the load distribution, it is suggested that bolts in the same column as or in the adjacent column to the missing fastener experience a notable growth in load. Meanwhile, if a bolt bears more loads in the pristine joint, the larger changes in stiffness, ultimate strength, and load distribution may be obtained when it is lost.

scholarly journals Vibration Analysis and Models of Adjacent Structures Controlled by Magnetorheological Dampers

2017 ◽  
Vol 2017 ◽  
pp. 1-21 ◽  
Author(s):  
Michela Basili ◽  
Maurizio De Angelis
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Vibration Analysis ◽  
Numerical Procedure ◽  
Mr Damper ◽  
Element Model ◽  
Shaking Table ◽  
Story Structure ◽  
Adjacent Structures ◽  
Definition Of

This paper deals with the vibration analysis of adjacent structures controlled by a magnetorheological (MR) damper and with the discussion of a numerical procedure for identification and definition of a reliable finite element model. The paper describes an extensive experimental campaign investigating the dynamic response, through shaking table tests, of a tridimensional four-story structure and a two-story structure connected by an MR device. Several base excitations and intensity levels are considered. The structures were tested in nonconnected and connected configuration, with the MR damper operating in passive or semiactive mode. Moreover, the paper illustrates a procedure for the structural identification and the definition of a reliable numerical model valid for adjacent structures connected by MR dampers. The procedure is applied in the original nonconnected configuration, which represents a linear system, and then in the connected configuration, which represents a nonlinear system due to the MR damper. In the end, the updated finite element model is reliable and suitable for all the considered configurations and the mass, damping, and stiffness matrices are derived. The experimental and numerical responses are compared and the results confirm the effectiveness of the identification procedure and the validation of the finite element model.

Structural Design and Analysis on Frame of Blueberry Harvesters Based on ANSYS

2010 ◽  
Vol 26-28 ◽  
pp. 794-799
Author(s):  
Qian Wang ◽  
Zhi Peng Li ◽  
Dao Qiang Wang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Static Analysis ◽  
Working Conditions ◽  
Structural Design ◽  
Mechanical Characteristics ◽  
Element Model ◽  
Frame Structure ◽  
Ansys Software ◽  
The Finite Element Model

The frame of blueberry harvesters is quite different from other vehicles. In this article, the design for whole frame structure is elaborated. According to the mechanical characteristics of the frame, materials are selected and manufacturability requirements are limited. Based on PRO/E software, accurate model of the frame of blueberry harvesters is established. And then, on the basis of ANSYS software, the finite element model of frame of blueberry harvesters is established to carry out static analysis on full-loaded and distortion working conditions. Results meet the strength requirements and displacement requirements, so it verifies the reasonableness of the design of frame.

scholarly journals Development of calculation procedure for research and refinement of suspended design natural frequencies by example of vehicle exhaust system

2021 ◽  
Vol 2061 (1) ◽  
pp. 012139
Author(s):  
R I Rakhmatov ◽  
V E Krutolapov ◽  
G G Nadareishvili ◽  
I V Malkin
Keyword(s):  
Finite Element ◽  
Mechanical Characteristics ◽  
Natural Frequencies ◽  
Exhaust System ◽  
Element Model ◽  
Calculation Procedure ◽  
Vehicle Exhaust ◽  
Oscillation Modes ◽  
Definition Of ◽  
Physical And Mechanical Characteristics

Abstract The article presents a finite element model exhaust system developed in the ANSA software package. Experimental research of the dynamic characteristics mounts exhaust system. and developed calculation procedure for improvement of the suspended design natural frequencies based on the experimental definition of boundary conditions by the example of the vehicle exhaust system. Requirements for natural frequencies of the exhaust system are developed; finite element models of the exhaust system are developed; physical and mechanical characteristics of mounts are defined; natural frequencies and oscillation modes of the exhaust system taking into account physical and mechanical characteristics of mounts are calculated.

scholarly journals Finite Element Analysis of Mechanical Characteristics of Dropped Eggs Based on Fluid-Solid Coupling Theory

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Song Haiyan ◽  
Wang Fang ◽  
Zhang Jianguo ◽  
Zhang Yinong ◽  
Yang Shugang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Mechanical Characteristics ◽  
Structural Parameters ◽  
Element Model ◽  
Coupling Theory ◽  
Element Analysis ◽  
Internal Fluid ◽  
Drop Impacts ◽  
Protective Packaging

It is important to study the properties and mechanics of egg drop impacts in order to reduce egg loss during processing and logistics and to provide a basis for the protective packaging of egg products. In this paper, we present the results of our study of the effects of the structural parameters on the mechanical properties of an egg using a finite element model of the egg. Based on Fluid-Solid coupling theory, a finite element model of an egg was constructed using ADINA, a finite element calculation and analysis software package. To simplify the model, the internal fluid of the egg was considered to be a homogeneous substance. The egg drop impact was simulated by the coupling solution, and the feasibility of the model was verified by comparison with the experimental results of a drop test. In summary, the modeling scheme was shown to be feasible and the simulation results provide a theoretical basis for the optimum design of egg packaging and egg processing equipment.

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