Numerical Analysis of SS316L Biaxial Cruciform Specimens Under Proportional Loading Paths

2021 ◽  
Author(s):  
Elizabeth M. Mamros ◽  
Matthew C. Eaton ◽  
Jinjin Ha ◽  
Brad L. Kinsey
Keyword(s):  
Biaxial Loading ◽  
High Strength ◽  
Martensite Phase ◽  
Patient Specific ◽  
Stainless Steel 316L ◽  
Proportional Loading ◽  
Broken Bones ◽  
Low Weight ◽  
The Us ◽  
Backscatter Diffraction

Abstract In this paper, finite element analyses were conducted to investigate the stress and strain states resulting from varying the deformation of stainless steel 316L under biaxial loading. To that end, a biaxial specimen geometry was designed in collaboration with the US National Institute of Standards and Technology (NIST) to achieve large and uniform strain values in the central pocket region. Special care was taken to ensure that the specimen design could be readily manufactured with available resources. Simultaneously, the specimen design criteria required an acceptable strain uniformity in a sufficiently large pocket section to allow for accurate deformation and austenite to martensite phase fraction measurements. This demonstrates the concept of altering the final material properties through stress superposition. Numerical results show that nearly linear curves were observed in the strain path plots. The minimum uniform deformation area for the 4:1 case had a radius of ∼1 mm, which is sufficient for experimental analyses, e.g., digital imaging correlation and electron beam backscatter diffraction. As an application for such heterogeneous materials, patient specific trauma fixation hardware, which are surgically implanted to set broken bones during healing, require high strength in areas where screws are located, i.e., martensite phase, yet low weight elsewhere.

MITTAL DI-FORM T700, HF80Y100T

Alloy Digest ◽  
2007 ◽  
Vol 56 (2) ◽  
Keyword(s):  
Automotive Industry ◽  
High Strength ◽  
Martensite Phase ◽  
Carbon Steels ◽  
Ferrite Phase ◽  
Dual Phase ◽  
Low Carbon ◽  
Advanced High Strength Steel ◽  
Dp Steels ◽  
Soft Ferrite

Abstract MITTAL DI-FORM T700 and HF80Y100T are low-carbon steels with a manganese and silicon composition. Dual-phase (DP) steels are one of the important advanced high-strength steel (AHSS) products developed for the automotive industry. Their microstructure typically consists of a soft ferrite phase with dispersed islands of a hard martensite phase. The martensite phase is substantially stronger than the ferrite phase. The DI-FORM grades exhibit low yield-to-tensile strengths, and the numeric designation in the name corresponds to the tensile strength. This datasheet provides information on microstructure and tensile properties as well as deformation and fatigue. It also includes information on forming. Filing Code: SA-561. Producer or source: Mittal Steel USA Flat Products.

MITTAL DI-FORM T590, T600

Alloy Digest ◽  
2007 ◽  
Vol 56 (1) ◽  
Keyword(s):  
Tensile Strength ◽  
Automotive Industry ◽  
High Strength ◽  
Martensite Phase ◽  
Ferrite Phase ◽  
Dual Phase ◽  
Bend Strength ◽  
Low Carbon ◽  
Advanced High Strength Steel ◽  
Soft Ferrite

Abstract MITTAL DI-FORM T590 and T600 are low-carbon dual-phase steels containing manganese and silicon. Dual-phase (DP) steels are important advanced high-strength steel (AHSS) products developed for the automotive industry. Their microstructure typically consists of a soft ferrite phase with dispersed islands of a hard martensite phase. The martensite phase is substantially stronger than the ferrite phase. The DI-FORM grades exhibit low yield-to-tensile strength ratios. The numeric designation in the grade name corresponds to the tensile strength in MPa. This datasheet provides information on microstructure, tensile properties, and bend strength as well as fatigue. It also includes information on forming. Filing Code: SA-558. Producer or source: Mittal Steel USA Flat Products.

scholarly journals Demographics associated with US healthcare disparities are exacerbated by the telemedicine surge during the COVID-19 pandemic

2021 ◽  
pp. 1357633X2110259
Author(s):  
Kristin N Gmunder ◽  
Jose W Ruiz ◽  
Dido Franceschi ◽  
Maritza M Suarez
Keyword(s):  
Income Tax ◽  
Healthcare Disparities ◽  
Descriptive Statistics ◽  
Internal Revenue Service ◽  
Patient Specific ◽  
Postal Code ◽  
The Us ◽  
Hispanic Patients ◽  
The Impact ◽  
Racial Ethnic

Introduction As coronavirus disease 2019 (COVID-19) hit the US, there was widespread and urgent implementation of telemedicine programs nationwide without much focus on the impact on patient populations with known existing healthcare disparities. To better understand which populations cannot access telemedicine during the coronavirus disease 2019 pandemic, this study aims to demographically describe and identify the most important demographic predictors of telemedicine visit completion in an urban health system. Methods Patient de-identified demographics and telemedicine visit data ( N = 362,764) between March 1, 2020 and October 31, 2020 were combined with Internal Revenue Service 2018 individual income tax data by postal code. Descriptive statistics and mixed effects logistic regression were used to determine impactful patient predictors of telemedicine completion, while adjusting for clustering at the clinical site level. Results Many patient-specific demographics were found to be significant. Descriptive statistics showed older patients had lower rates of completion ( p < 0.001). Also, Hispanic patients had statistically significant lower rates ( p < 0.001). Overall, minorities (racial, ethnic, and language) had decreased odds ratios of successful telemedicine completion compared to the reference. Discussion While telemedicine use continues to be critical during the coronavirus disease 2019 pandemic, entire populations struggle with access—possibly widening existing disparities. These results contribute large datasets with significant findings to the limited research on telemedicine access and can help guide us in improving telemedicine disparities across our health systems and on a wider scale.

scholarly journals Multiaxial fatigue study on steel transversal attachments under constant amplitude proportional and non-proportional loadings

2018 ◽  
Vol 165 ◽  
pp. 16007
Author(s):  
Martin Garcia ◽  
Claudio A. Pereira Baptista ◽  
Alain Nussbaumer
Keyword(s):  
Fatigue Life ◽  
High Strength ◽  
Fatigue Tests ◽  
Multiaxial Fatigue ◽  
Life Assessment ◽  
Experimental Program ◽  
Proportional Loading ◽  
Load Carrying ◽  
Stress States ◽  
Experimental Values

In this study, the multiaxial fatigue strength of full-scale transversal attachment is assessed and compared to original experimental results and others found in the literature. Mild strength S235JR steel is used and an exploratory investigation on the use of high strength S690QL steel and the effect of non-proportional loading is presented. The study focuses on non-load carrying fillet welds as commonly used in bridge design and more generally between main girders and struts. The experimental program includes 33 uniaxial and multiaxial fatigue tests and was partially carried out on a new multiaxial setup that allows proportional and non-proportional tests in a typical welded detail. The fatigue life is then compared with estimations obtained from local approaches with the help of 3D finite element models. The multiaxial fatigue life assessment with some of the well-known local approaches is shown to be suited to the analysis under multiaxial stress states. The accuracy of each models and approaches is compared to the experimental values considering all the previously cited parameters.

scholarly journals Initiation and short crack growth behaviour of environmentally induced cracks in AA5083 H131 investigated across time and length scales

2019 ◽  
Vol 37 (5) ◽  
pp. 469-481 ◽  
Author(s):  
Visweswara C. Gudla ◽  
Alistair Garner ◽  
Malte Storm ◽  
Parmesh Gajjar ◽  
James Carr ◽  
...  
Keyword(s):  
Electron Backscatter Diffraction ◽  
Three Dimensional ◽  
High Strength ◽  
Time Lapse ◽  
Growth Behaviour ◽  
Spectroscopy Analysis ◽  
Crack Growth Behaviour ◽  
Rate Testing ◽  
X Ray Computed ◽  
Backscatter Diffraction

AbstractEnvironmentally induced cracking (EIC) in a sensitized high-strength AA5083 H131 alloy has been investigated using time-lapse synchrotron X-ray computed tomography combined with post-mortem correlative characterization. Small corrosion features deliberately introduced in a pre-exposure step were found to be the site of initiation for over 95% of the 44 EIC cracks that developed under slow strain rate testing. Detailed analysis using three-dimensional electron backscatter diffraction and energy-dispersive spectroscopy analysis of a single crack confirmed the intergranular nature of the cracks from the start and that the pre-exposure corrosion was associated with an α-AlFeMnSi particle cluster. It also appears that several cracks may have initiated at this site, which later coalesced to form the 300-μm-long crack that ultimately developed. Of further note is the fact that initiation of the EIC cracks across the sample started below the yield strength and continued beyond the ultimate tensile strength. The most rapid crack propagation occurred during sample extension following a period of fixed displacement.

scholarly journals High strength and low weight hollow carbon fibres

2017 ◽  
Vol 254 ◽  
pp. 042017 ◽  
Author(s):  
T. Köhler ◽  
R. Brüll ◽  
F. Pursche ◽  
J. Langgartner ◽  
G. Seide ◽  
...  
Keyword(s):  
High Strength ◽  
Carbon Fibres ◽  
Low Weight ◽  
Hollow Carbon

scholarly journals Simplified Material Solution for Orthotropic Symmetrical GFRP Laminates for Structural Facades

2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
Yuchao Zhao ◽  
Xu Jiang ◽  
Qilin Zhang ◽  
Xuhong Qiang
Keyword(s):  
Design Theory ◽  
High Strength ◽  
Fiber Reinforced Polymer ◽  
Free Form ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Complex Design ◽  
Low Weight ◽  
Strength And Stiffness ◽  
Material Solution

GFRP (glass-fiber-reinforced polymer), as a composite material, possesses many favorable properties including high strength and low weight and is amenable to unique processing methods; therefore, it is a potential free-form surface material. However, the complex design theory owing to anisotropy limits its application. Thus, a simplified material solution becomes significant. In this study, the strength and stiffness of orthotropic symmetrical GFRP laminates are derived theoretically, and a simplified material solution is proposed to simplify the anisotropy as isotropy. Then, using the numerical simulation of an actual orthotropic symmetrical GFRP laminate free-form facade structure, the effectiveness of the simplified material solution is analyzed and evaluated. This solution can provide guidance for similar GFRP facades and further promote the application of GFRP in engineering.

Use of the Photoelastic Method to Determine the Wall Stress in Realistic Abdominal Aortic Aneurysm Models

2011 ◽  
Author(s):  
Barry J. Doyle ◽  
Anthony Callanan ◽  
John Killion ◽  
Timothy M. McGloughlin
Keyword(s):  
Wall Stress ◽  
Aortic Aneurysms ◽  
Maximum Diameter ◽  
Patient Specific ◽  
Western World ◽  
Photoelastic Method ◽  
Element Analysis ◽  
Abdominal Aortic ◽  
The Us ◽  
Numerical Tools

Abdominal aortic aneurysms (AAAs) remain a significant cause of death in the Western world with over 15,000 deaths per year in the US linked to AAA rupture. Recent research [1] has questioned the use of maximum diameter as a definitive risk parameter as it is now believed that alternative factors may be important in rupture-prediction. Wall stress was shown to be a better predictor than diameter of rupture [1], with biomechanics-based rupture indices [2,3] and asymmetry also reported to have potential clinical applicability [4]. However, the majority of numerical methods used to form these alternative rupture parameters are without rigorous experimental validation, and therefore may not be as accurate as believed. Validated experiments are required in order to convince the clinical community of the worth of numerical tools such as finite element analysis (FEA) in AAA risk-prediction. Strain gauges have been used in the past to determine the strain on an AAA [5], however, the photoelastic method has also proved to be a useful tool in AAA biomechanics [6]. This paper examines the approach using three medium-sized patient-specific AAA cases at realistic pressure loadings.

scholarly journals Interface Characteristics and Properties of a High-Strength Corrosion-Resistant Stainless Steel Clad Rebar

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 373
Author(s):  
Xuming Liu ◽  
Guanghong Feng ◽  
Xin Liu ◽  
Baoshan Wang ◽  
Hongliang Zhang ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Transition Zone ◽  
High Strength ◽  
Martensite Phase ◽  
Duplex Structure ◽  
Bending Tests ◽  
Metallurgical Bonding ◽  
Interface Characteristics ◽  
Rolling Method ◽  
Negative Bending

This paper aims at manufacturing stainless steel clad (SSC) rebars by metal deposition and a hot rolling method as well as characterizing its interface features and mechanical properties. The interface of the SSC rebar is relatively flat and clean, exhibiting a metallurgical bonding state at the microscale. Decarburization occurred at the interface in the carbon steel side of the SSC rebar. The diffusion of C, Cr, as well as Mn was measured across the interface of the SSC rebar, and the diffusion distance of Cr and Mn was found at 32 µm and 25 µm, respectively. The Vickers hardness testing in the transition zone of the SSC rebar near the carbon side showed 545 HV0.2 due to the martensite phase formed by the diffusion of key elements C, Cr, and Mn. The microstructure in the transition zone near the stainless steel reveals the duplex structure of martensite and ferrite. The carbide precipitations were observed near the interface, both in the transition zone and in the base metal of the stainless steel zone. The yield strength, tensile strength, and elongation of the SSC rebar were found as 423 MPa, 602 MPa, and 22%. No macroscopic crack was observed after the positive or negative bending tests.

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