Material Behaviour and Limits of Cracking in Powder Preform Forging

1977 ◽  
pp. 489-496
Author(s):  
M. Negm ◽  
R. Davies
Keyword(s):  
Material Behaviour ◽  
Powder Preform

scholarly journals Study of biaxial mechanical properties of the passive pig heart: material characterisation and categorisation of regional differences

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Fulufhelo Nemavhola
Keyword(s):  
Mechanical Properties ◽  
Constitutive Model ◽  
Computational Models ◽  
Heart Diseases ◽  
Interventricular Septum ◽  
Model Material ◽  
Biaxial Test ◽  
Material Behaviour ◽  
Material Parameters ◽  
Biaxial Tests

AbstractRegional mechanics of the heart is vital in the development of accurate computational models for the pursuit of relevant therapies. Challenges related to heart dysfunctioning are the most important sources of mortality in the world. For example, myocardial infarction (MI) is the foremost killer in sub-Saharan African countries. Mechanical characterisation plays an important role in achieving accurate material behaviour. Material behaviour and constitutive modelling are essential for accurate development of computational models. The biaxial test data was utilised to generated Fung constitutive model material parameters of specific region of the pig myocardium. Also, Choi-Vito constitutive model material parameters were also determined in various myocardia regions. In most cases previously, the mechanical properties of the heart myocardium were assumed to be homogeneous. Most of the computational models developed have assumed that the all three heart regions exhibit similar mechanical properties. Hence, the main objective of this paper is to determine the mechanical material properties of healthy porcine myocardium in three regions, namely left ventricle (LV), mid-wall/interventricular septum (MDW) and right ventricle (RV). The biomechanical properties of the pig heart RV, LV and MDW were characterised using biaxial testing. The biaxial tests show the pig heart myocardium behaves non-linearly, heterogeneously and anisotropically. In this study, it was shown that RV, LV and MDW may exhibit slightly different mechanical properties. Material parameters of two selected constitutive models here may be helpful in regional tissue mechanics, especially for the understanding of various heart diseases and development of new therapies.

Design of SPF Dies Based on Advanced Material Behaviour Models

2004 ◽  
Vol 447-448 ◽  
pp. 123-130 ◽  
Author(s):  
Gérard Bernhart ◽  
F. Nazaret ◽  
A. Martinier ◽  
C. Gao ◽  
D. Garriga-Majo ◽  
...  
Keyword(s):  
Material Behaviour ◽  
Advanced Material ◽  
Behaviour Models

scholarly journals Non-local criteria for the borehole problem: Gradient Elasticity versus Finite Fracture Mechanics

Meccanica ◽  
2021 ◽  
Author(s):  
A. Sapora ◽  
G. Efremidis ◽  
P. Cornetti
Keyword(s):  
Stress Concentration ◽  
Fracture Mechanics ◽  
Elastic Material ◽  
Fracture Criterion ◽  
Biaxial Loading ◽  
Gradient Elasticity ◽  
Energy Conditions ◽  
Material Behaviour ◽  
Finite Fracture Mechanics ◽  
Non Local

AbstractTwo nonlocal approaches are applied to the borehole geometry, herein simply modelled as a circular hole in an infinite elastic medium, subjected to remote biaxial loading and/or internal pressure. The former approach lies within the framework of Gradient Elasticity (GE). Its characteristic is nonlocal in the elastic material behaviour and local in the failure criterion, hence simply related to the stress concentration factor. The latter approach is the Finite Fracture Mechanics (FFM), a well-consolidated model within the framework of brittle fracture. Its characteristic is local in the elastic material behaviour and non-local in the fracture criterion, since crack onset occurs when two (stress and energy) conditions in front of the stress concentration point are simultaneously met. Although the two approaches have a completely different origin, they present some similarities, both involving a characteristic length. Notably, they lead to almost identical critical load predictions as far as the two internal lengths are properly related. A comparison with experimental data available in the literature is also provided.

Material behaviour characterization of Friction Stir Spot Welding of Copper

2017 ◽  
Vol 4 (2) ◽  
pp. 166-177 ◽  
Author(s):  
Esther T. Akinlabi ◽  
Kazeem O. Sanusi ◽  
Edison Muzenda ◽  
Stephen A. Akinlabi
Keyword(s):  
Spot Welding ◽  
Friction Stir Spot Welding ◽  
Material Behaviour ◽  
Friction Stir

Analysis of Material Behaviour in Experimental and Simulative Setup of Joining by Forming of Aluminium Alloy and High Strength Steel with Shear-Clinching Technology

2014 ◽  
Vol 966-967 ◽  
pp. 549-556 ◽  
Author(s):  
Martin Müller ◽  
Réjane Hörhold ◽  
Marion Merklein ◽  
Gerson Meschut
Keyword(s):  
High Strength ◽  
Cost Effective ◽  
Metallic Materials ◽  
Material Behaviour ◽  
Transportation Sector ◽  
Reference Process ◽  
Key Factor ◽  
Mechanical Clinching ◽  
Safety Parameters ◽  
Systematic Development

In transportation sector the reduction of moving masses without the decrease of safety parameters is a key factor for future economic success. One possible approach for this is the use of different metallic materials in composite construction. Therefore, it is essential to establish a reliable component connection by means of suitable and cost-effective joining technologies. Mechanical joining technologies such as self-piercing riveting and mechanical clinching have proven to be effective methods for joining lightweight materials like aluminium and ductile steels. As these technologies require formability or pre-holing of the joining partners, the field of application is limited by the mechanical properties of the joining partners. Great potential for joining hot stamped steels, which have a very low elongation at fracture and therefore a low formability, offers the shear-clinching technology. For a systematic development of the shear-clinching technology, detailed investigations of the process are required. This paper presents an analysis of the material behaviour during the shear-clinching process and the reference process – clinching with pre-hole.

The Fatigue Behaviour of a High Strength CrNi-Steel Regarding Fretting Fatigue

2012 ◽  
Author(s):  
Thomas Christiner ◽  
Johannes Reiser ◽  
István Gódor ◽  
Wilfried Eichlseder ◽  
Franz Trieb ◽  
...  
Keyword(s):  
High Strength ◽  
Contact Problems ◽  
Fatigue Behaviour ◽  
Fretting Fatigue ◽  
Service Performance ◽  
Fatigue Properties ◽  
Material Behaviour ◽  
Reliable Prediction ◽  
Damage And Failure ◽  
Lubrication Conditions

In many assemblies of moving components, contact problems under various lubrication conditions are lifetime-limiting. There, relative motion of contacting bodies, combined with high loads transmitted via the contact surface lead to fretting fatigue failure. For a reliable prediction of in service performance load type, different damage and failure mechanisms that may be activated during operation have to be known. In this contribution selected results of a currently conducted research project are presented. The aim of this study was to examine the material behaviour of a surface stressed steel. The influence of the fretting regime on fatigue properties has been investigated.

A Study on the Coupled Thermal and Damage Effects in Deforming Solids

2011 ◽  
Vol 312-315 ◽  
pp. 229-234
Author(s):  
M. Vaz ◽  
Pablo A. Muñoz-Rojas ◽  
M.R. Lange
Keyword(s):  
Metal Forming ◽  
Ductile Failure ◽  
Tensile Tests ◽  
Thermal Softening ◽  
Mechanical Degradation ◽  
Material Behaviour ◽  
Temperature Variations ◽  
Damage Models ◽  
Notched Specimens ◽  
Fully Coupled

Mechanical degradation and ductile failure in metal forming operations can be successfully modelled using fully coupled damage models. In addition, it has been largely reported in the literature that temperature variations affect material behaviour, especially thermal softening. This paper presents a numerical discussion of the coupled effects between ductile damage and temperature evolution based on the simulation of tensile tests of notched specimens.

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