A Note on Tire Carcass Mechanical Properties

1978 ◽  
Vol 6 (4) ◽  
pp. 248-262
Author(s):  
J. T. Tielking ◽  
R. E. Martin ◽  
R. A. Schapery
Keyword(s):  
Mechanical Properties ◽  
Material Properties ◽  
Geometric Nonlinearity ◽  
Elastic Stress ◽  
Uniaxial Stress ◽  
Element Model ◽  
Stress Tests ◽  
Linear Elastic ◽  
Constituent Material

Abstract Uniaxial stress tests were conducted on composite specimens cut from two different locations on a bias tire carcass. These data together with cord data, the Halpin-Tsai “micromechanics” equations, and the linear laminate constitutive equations are used to derive the in-situ rubber modulus as a function of time and to check for consistency among the specimens tested. The main purpose of the first part of the study was to obtain constituent material properties for use in a finite element model of a tire. This model is then employed in the investigation of the influence of uniform rubber modulus on the shape of an inflated tire carcass, and it is concluded that the strain and time dependence of the rubber modulus will introduce some error in a tire structural analysis that uses linear elastic stress-strain equations and permits geometric nonlinearity. It appears that the error will be minimal in a low strain region such as in the sidewall.

Finite element simulation of folding carton erection failure

2007 ◽  
Vol 221 (7) ◽  
pp. 753-767 ◽  
Author(s):  
D M Sirkett ◽  
B J Hicks ◽  
C Berry ◽  
G Mullineux ◽  
A J Medland
Keyword(s):  
Finite Element ◽  
Material Properties ◽  
High Speed ◽  
Element Model ◽  
Machine Material ◽  
Linear Elastic ◽  
Element Simulation ◽  
Packaging Industry ◽  
First Time ◽  
The Eu

In response to recent European Union (EU) regulations on packaging waste, the packaging industry requires greater fundamental understanding of the machine-material interactions that take place during packaging operations. Such an understanding is necessary to handle thinner lighter-weight materials, specify the material properties required for successful processing and design right-first-time machinery. The folding carton industry, in particular, has been affected by the new legislation and needs to realize the potential of computational tools for simulating the behaviour of packaging materials and generating the necessary understanding. This paper describes the creation and validation of a detailed finite element model of a carton during a common packaging operation. The model is applied here to address the problem of carton buckling. The carton was modelled using a linear elastic material definition with non-linear crease behaviour. Air inrush suction, which is believed to cause buckling, was quantified experimentally and incorporated using contact damping interactions. The results of the simulation are validated against high-speed video of carton production. The model successfully predicts the pattern of deformation of the carton during buckling and its increasing magnitude with production rate. The model can be applied to study the effects of variation in material properties, pack properties and machine settings. Such studies will improve responsiveness to change and will ultimately allow end-users to use thinner, lighter-weight materials in accordance with the EU regulations.

Tribological Process Characterization With In-Situ Quantitative Nano-Scale Metrology

2005 ◽  
Author(s):  
Antanas Daugela ◽  
Alex Meyman ◽  
Vladimir Knyazik ◽  
Nikolai Yeremin
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Optical Microscope ◽  
Nano Scale ◽  
Process Characterization ◽  
Microscope Imaging

A novel quantitative nano+micro-tribometer with integrated nanoindenter, SPM and optical microscope imaging has been used to characterize mechanical properties of Cu coated Si wafers at various test stages. A 2D Finite Element Model was developed to study changes on workhardened contacts assessed via nanoindentation experiments.

Computational Analysis of Microstructure of Ultra High Molecular Weight Polyethylene for Total Joint Replacement

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Kelly M. Seymour ◽  
Sara A. Atwood
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Finite Element ◽  
Finite Element Model ◽  
High Molecular Weight ◽  
Element Model ◽  
Experimental Results ◽  
Linear Elastic ◽  
Ultra High Molecular Weight ◽  
Scanning Electron

Ultra high molecular weight polyethylene (UHMWPE, or ultra high), a frequently used material in orthopedic joint replacements, is often the cause of joint failure due to wear, fatigue, or fracture. These mechanical failures have been related to ultra high's strength and stiffness, and ultimately to the underlying microstructure, in previous experimental studies. Ultra high's semicrystalline microstructure consists of about 50% crystalline lamellae and 50% amorphous regions. Through common processing treatments, lamellar percentage and size can be altered, producing a range of mechanical responses. However, in the orthopedic field the basic material properties of the two microstructural phases are not typically studied independently, and their manipulation is not computationally optimized to produce desired mechanical properties. Therefore, the purpose of this study is to: (1) develop a 2D linear elastic finite element model of actual ultra high microstructure and fit the mechanical properties of the microstructural phases to experimental data and (2) systematically alter the dimensions of lamellae in the model to begin to explore optimizing the bulk stiffness while decreasing localized stress. The results show that a 2D finite element model can be built from a scanning electron micrograph of real ultra high lamellar microstructure, and that linear elastic constants can be fit to experimental results from those same ultra high formulations. Upon altering idealized lamellae dimensions, we found that bulk stiffness decreases as the width and length of lamellae increase. We also found that maximum localized Von Mises stress increases as the width of the lamellae decrease and as the length and aspect ratio of the lamellae increase. Our approach of combining finite element modeling based on scanning electron micrographs with experimental results from those same ultra high formulations and then using the models to computationally alter microstructural dimensions and properties could advance our understanding of how microstructure affects bulk mechanical properties. This advanced understanding could allow for the engineering of next-generation ultra high microstructures to optimize mechanical behavior and increase device longevity.

scholarly journals Deformation Behavior of C15E + C Steel under Different Uniaxial Stress Tests

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1445
Author(s):  
Josip Brnic ◽  
Marino Brcic ◽  
Sanjin Krscanski ◽  
Jitai Niu ◽  
Sijie Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Yield Strength ◽  
Creep Behavior ◽  
Room Temperature ◽  
Experimental Tests ◽  
Uniaxial Stress ◽  
Cyclic Fatigue ◽  
Fatigue Tests ◽  
Stress Tests

In this paper, the mechanical properties of the material that define its mechanical behavior are experimentally investigated. All performed experimental tests and analyzes are related to C15E + C steel. The tested material was delivered as cold drawn round bar. It is usually used in mechanical engineering for design of low stressed components. Experimentally obtained results relate to the maximum tensile strength, yield strength, creep behavior, and uniaxial fully reversed high cyclic fatigue. Results representing mechanical properties are shown in the form of engineering stress–strain diagrams, while creep behavior of the material at different temperatures and different stress levels is displayed in the form of creep curves. Tests representing uniaxial cyclic fully reversed mechanical fatigue at constant stresses and room temperature in air are shown in the form of fatigue-life (S−N) diagram. Some of the experimental results obtained are as follows: ultimate tensile strength (σm(20 °C/500 °C)=(598/230) MPa), yield strength (σ0.2(20 °C/500 °C)=(580/ 214 ) MPa ), modulus of elasticity (E(20 °C/500 °C)=(213/106) GPa), and fatigue limit (σf(20 °C, R=−1)=250.83 MPa). The fatigue tests were performed at frequency of 40 Hz and at room temperature (20 °C) in air, with stress ratio of R=−1.

A regenerative approach towards recovering the mechanical properties of degenerated intervertebral discs: Genipin and platelet-rich plasma therapies

2016 ◽  
Vol 231 (2) ◽  
pp. 127-137 ◽  
Author(s):  
Mohammad Nikkhoo ◽  
Jaw-Lin Wang ◽  
Masoud Abdollahi ◽  
Yu-Chun Hsu ◽  
Mohamad Parnianpour ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Material Properties ◽  
Degenerative Disc Disease ◽  
Structural Changes ◽  
Ex Vivo ◽  
Platelet Rich Plasma ◽  
Element Model ◽  
Intervertebral Discs ◽  
Disc Disease ◽  
Degenerative Disc

Degenerative disc disease, associated with discrete structural changes in the peripheral annulus and vertebral endplate, is one of the most common pathological triggers of acute and chronic low back pain, significantly depreciating an individual’s quality of life and instigating huge socioeconomic costs. Novel emerging therapeutic techniques are hence of great interest to both research and clinical communities alike. Exogenous crosslinking, such as Genipin, and platelet-rich plasma therapies have been recently demonstrated encouraging results for the repair and regeneration of degenerated discs, but there remains a knowledge gap regarding the quantitative degree of effectiveness and particular influence on the mechanical properties of the disc. This study aimed to investigate and quantify the material properties of intact (N = 8), trypsin-denatured (N = 8), Genipin-treated (N = 8), and platelet-rich plasma–treated (N = 8) discs in 32 porcine thoracic motion segments. A poroelastic finite element model was used to describe the mechanical properties during different treatments, while a meta-model analytical approach was used in combination with ex vivo experiments to extract the poroelastic material properties. The results revealed that both Genipin and platelet-rich plasma are able to recover the mechanical properties of denatured discs, thereby affording promising therapeutic modalities. However, platelet-rich plasma–treated discs fared slightly, but not significantly, better than Genipin in terms of recovering the glycosaminoglycans content, an essential building block for healthy discs. In addition to investigating these particular degenerative disc disease therapies, this study provides a systematic methodology for quantifying the detailed poroelastic mechanical properties of intervertebral disc.

scholarly journals Pressure stimulated currents in rocks and their correlation with mechanical properties

2004 ◽  
Vol 4 (4) ◽  
pp. 563-567 ◽  
Author(s):  
I. Stavrakas ◽  
D. Triantis ◽  
Z. Agioutantis ◽  
S. Maurigiannakis ◽  
V. Saltas ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cyclic Loading ◽  
Young Modulus ◽  
Uniaxial Stress ◽  
Aftershock Sequence ◽  
Earthquake Precursors ◽  
Experimental Results ◽  
Loading Cycle ◽  
Linear Elastic ◽  
Maximum Value

Abstract. The spontaneous electrification of marble samples was studied while they were subjected to uniaxial stress. The Pressure Stimulated Current (PSC) technique was applied to measure the charge released from compressed Dionysos marble samples, while they were subjected to cyclic loading. The experimental results demonstrate that, in the linear elastic region of the sample, no PSC is recorded, while beyond the stress limit (s>0.60), observable variations appear, which increase considerably in the vicinity of sample failure, reaching a maximum value just before the failure. The emitted current is reduced on each loading cycle and it has a reciprocal dependence to the normalized Young modulus. The MCD model, applied out of the vicinity of sample failure explains successfully the above findings. The existence of a "memory-like" behavior of the sample, could justify the weakness or absence of electrical earthquake precursors, during an aftershock sequence.

Microstructural Design by Selective Grain Growth of β-Si3N4

1992 ◽  
Vol 287 ◽  
Author(s):  
Naoto Hirosaki ◽  
Yoshio Akimune ◽  
Mamoru Mitomo
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Material Properties ◽  
Weibull Modulus ◽  
Sintered Material ◽  
High Reliability ◽  
Uniform Size ◽  
Microstructural Design ◽  
Sintering Conditions

ABSTRACTRaw β-Si3N4 powder was gas-pressure sintered with Y2 O3-Nd2O3additives at > 1700ºC. Graingrowth behavior was investigated in relation to sintering conditions. Selective growth of large grains was accomplished by sintering the powder at high temperatures with small amounts of additives. As a result, in-situ composites were obtained from β-powder.The desired material properties have been attained by controlling the microstructural design using large grains. Materials with high reliability, having a Weibull modulus of about 50, were fabricated by maintaining a uniform size and distribution of elongated grains. Tough materials, having fracture toughness of, were developed by increasing the diameter of elongated grains. This method was applied to the sintering of refractory grade powder with the aim of lowering sintered material cost. Fairly good mechanical properties have been obtained even with impure powders.

Extracellular Matrix-Contractile Response Coupling of the Aortic Heart Valve Interstitial Cell

2008 ◽  
Author(s):  
David E. Schmidt ◽  
W. David Merryman ◽  
Michael S. Sacks
Keyword(s):  
Mechanical Properties ◽  
Extracellular Matrix ◽  
Aortic Valve ◽  
Interstitial Cell ◽  
Mechanical Response ◽  
Element Model ◽  
Multi Scale ◽  
Aortic Heart Valve ◽  
Composition And Structure

The role of aortic valve interstitial cell (AVIC) and extracellular matrix (ECM) interactions of the aortic valve (AV) are not well understood. Distinct differences in the composition and structure of the AV leaflet layers (fibrosa and ventricularis) have been shown to influence mechanical properties 1. Our ability to measure the effects of changes in cellular stiffness in the dense collagenous AV leaflets (AVL) 2 offers a unique opportunity to explore the in-situ AVIC stiffness and local AVIC-ECM mechanical interactions. In the present study, a multi-scale finite element model approach was developed based on our simulations of our flexural stiffness experiment 2 were used to develop effective layer dependent mechanical properties. In addition, we present a predictive model for the alteration of AVL tissue mechanical properties resulting from AVIC contraction. This model provides a means to probe the layer dependent properties under the influence of AVIC contraction relative to an intact tissue state. By establishing a procedure to examine ECM stiffness in situ, through coupled experimental and computational methods, insights into relative contributions of ECM components were developed. Finally, in contrast previous study, where tissue stiffness was reported in terms on an instantaneous elastic modules, this work provides a more complete mechanical response of AVL in flexure.

scholarly journals Numerical simulation of elastic stress in the microstructure of snow

2004 ◽  
Vol 38 ◽  
pp. 339-342 ◽  
Author(s):  
Martin Schneebeli
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Elastic Moduli ◽  
Elastic Stress ◽  
Element Model ◽  
Strain Rate Effect ◽  
Three Dimensions ◽  
Serial Sections ◽  
Stress Concentrations ◽  
X Ray

AbstractThe mechanical properties of snow depend on its microstructure. The fabric of snow was reconstructed in three dimensions using serial sections or X-ray microtomography. A voxel-based finite-element model, with the elements based on the microstructure and ice as the material, was used to calculate the stress distribution in the snow. A small elastic deformation was simulated and the bulk elastic moduli of these samples were determined. The simulated elastic modulus was 3–10 times or 10–100 times larger than previously published measurements. The deviation is possibly caused by the relatively slow deformation rates of the usual tests. This strain-rate effect is well known for pure ice. Locations of stress concentrations can be extracted and compared to the micro-structural location of bonds. By this method we are able to determine mechanical properties of thin or extremely brittle snow layers which are otherwise difficult or impossible to measure.

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