Structure of the metallurgically oriented modelling system TK-StripCam for simulation of hot strip manufacture and application in research and production practice

2004 ◽  
Vol 120 ◽  
pp. 801-808
Author(s):  
U. Lotter ◽  
H.-P. Schmitz ◽  
L. Zhang
Keyword(s):  
Mechanical Properties ◽  
Simulation System ◽  
Physical Models ◽  
Computer Assisted ◽  
Microstructural Parameters ◽  
Hot Strip ◽  
Production Practice ◽  
Prediction Of Mechanical Properties ◽  
The One ◽  
Kinetics Of

For the prediction of mechanical properties of hot strip from production conditions by metallurgically oriented computer assisted simulation it is necessary to model all the numerous metallurgical processes leading to the microstructure of the finished product. The relevant microstructural parameters, calculated in this way, finally are converted into mechanical properties by application of suitable algorithms. At ThyssenKrupp Stahl such a metallurgically oriented simulation system has been developed and established under the name TK-StripCam. It is based on empirical-physical models. It allows on the one hand to predict important mechanical properties with considerable precision from production parameters as rolling schedule, cooling conditions etc. On the other hand by means of the simulation system course and kinetics of each metallurgical process included may be studied. It is evident that in a steel plant such a powerful tool finds a great variety of applications extending from offline use as a tool for development of steels and processes to inline use in the rolling mill to control the mechanical properties during production. In this work details of the philosophy and structure of the simulation system and examples for its application are presented.

Computer Assisted Femoral Augmentation: Modeling and Experimental Validation

2013 ◽  
Author(s):  
Ehsan Basafa ◽  
Ryan J. Murphy ◽  
Michael D. Kutzer ◽  
Yoshito Otake ◽  
Mehran Armand
Keyword(s):  
Mechanical Properties ◽  
Bone Cement ◽  
Experimental Validation ◽  
Particle Method ◽  
Computer Assisted ◽  
Injection Device ◽  
Pmma Bone Cement ◽  
Ct Data ◽  
Scan Data ◽  
The One

We report the results of planning and experimental validation of femoroplasty — augmentation of mechanical properties of the bone using polymethylmethacrylate (PMMA) bone cement injection — on osteoporotic femurs. For six pairs of osteoporotic femurs, finite element (FE) models were created using computed tomography (CT) scan data and an evolutionary method was used to optimize the cement pattern in one of the models from each pair. Using a particle method and the CT data, cement diffusion was modeled for several hypothetical augmentations and the one most closely matching the optimized pattern was chosen as the best plan. We used intra-operative navigation and a custom-designed injection device to deliver the cement into the bones precisely according to the plan. All femurs were then tested mechanically in a configuration simulating a fall to the side. Augmentation with this technique resulted in an increase in the yield load (28%) and yield energy (142%) compared to the control specimens, while only 9.8ml of cement was injected on average. Results support our hypothesis that significant improvements in the mechanical properties of osteoporotic femurs can be achieved by using minimal, and hence safe, amounts of PMMA bone cement.

scholarly journals Prediction Of Mechanical Properties Of Quench Hardening Steel

2015 ◽  
Vol 46 (1) ◽  
pp. 26-32 ◽  
Author(s):  
R. Chotěborský ◽  
M. Linda
Keyword(s):  
Mechanical Properties ◽  
Avrami Equation ◽  
Metallographic Analysis ◽  
Continuous Cooling ◽  
Hardness Tests ◽  
Alloy Steels ◽  
Diffusion Phase ◽  
Quench Hardening ◽  
Prediction Of Mechanical Properties ◽  
Kinetics Of

Abstract The present study investigated the application of finite element method for prediction of mechanical properties of quench hardening steel. Based on the experimental results obtained, a numerical model for simulation of continuous cooling of quench hardening steel was developed. For the simulation of the kinetics of diffusion phase transformations, the Avrami equation and additive rule were applied. A new model was also developed for martensitic transformation which was validated using metallographic analysis and hardness tests. Experimental and simulation results indicated a good agreement. The developed model information provided here could be used for simulation of continuous cooling and kinetics phase transformation as well as for prediction of final distribution of microstructures and hardness of alloy steels.

Understanding motility dynamics of crossbred bull spermatozoa when analyzed by Computer Assisted Semen Analyzer (CASA)

2017 ◽  
Author(s):  
Saroj Rai ◽  
S. Tyagi ◽  
M. Kumar ◽  
M. Karunakaran ◽  
M. Mondal ◽  
...  
Keyword(s):  
Circular Path ◽  
Computer Assisted ◽  
Low Velocity ◽  
Head Displacement ◽  
Semen Collection ◽  
Straight Line ◽  
Slow Moving ◽  
The One ◽  
Kinetics Of ◽  
Lateral Head

The study was conducted to understand sperm kinetics of Frieswal bull spermatozoa using Computer Assisted Semen Analyzer (CASA). Fifty bull ejaculates were collected from ten healthy bulls that were in routine semen collection. The semen samples were diluted in Tris buffer at a concentration of 25x106 spermatozoa/ ml for analysis. Rapidly moving spermatozoa represented the one with better velocity and progressiveness while spermatozoa with medium motility had low velocity with short distance travelled in spite of its ability to move in a straight line (straightness, STR >70 %). The slow moving cells had good head and flagella movement but they followed a circular path with straight line velocity (VSL mm/ sec), linearity (LIN %) and straightenss (STR %) of 10.91, 9.00 and 22.54, respectively. Results indicated that individual sperm cells tracked by CASA as rapid, medium and slow motile were highly variable (p>0.001). However, the sperm motility between bulls varied (p>0.05) only in lateral head displacement (ALH, mm) and beat cross frequency (BCF, Hz).

Arrangement Of Monomeric Units In Fibrin

1979 ◽  
Author(s):  
Jan Hermans
Keyword(s):  
Fiber Axis ◽  
High Symmetry ◽  
Linear Polymers ◽  
Fiber Volume ◽  
High Fiber ◽  
Rotation Axes ◽  
Small Set ◽  
Helical Turn ◽  
The One ◽  
Kinetics Of

Measurements of light scattering have given much information about formation and properties of fibrin. These studies have determined mass-length ratio of linear polymers (protofibrils) and of fibers, kinetics of polymerization and of lateral association and volume-mass ratio of thick fibers. This ratio is 5 to 1. On the one hand, this high value suggests that the fiber contains channels that allow the diffusion of enzymes such as Factor XHIa and plasmin; on the other hand, the high value appears paradoxical for a stiff fiber made up of elongated units (fibrin monomers) arranged in parallel. Such a high fiber volume is a property of only a small set out of many high-symmetry models of fibrin, which may be constructed from overlapping three-domain monomers which are arranged into strands, are aligned nearly parallel to the fiber axis and make adequate longitudinal and lateral contacts. These models contain helical protofibrils related to each other by rotation axes parallel to the fiber axis. The protofibrils may contain 2, 3 or 4 monomers per helical turn and there are four possible symmetries. A large specific volume is achieved if the ends of each monomer are slightly displaced from the protofibril axis, either by a shift or by a tilt of the monomer. The fiber containing tilted monomers is more highly interconnected; the two ends of a tilted monomer form lateral contacts with different adjacent protofibrils, whereas the two ends of a non-tilted monomer contact the same adjacent protofibril(s).

Elaboration and Characterization of the Properties of Refractory Cr Base Alloys

2010 ◽  
Vol 72 ◽  
pp. 46-52 ◽  
Author(s):  
Laurent Royer ◽  
Stéphane Mathieu ◽  
Christophe Liebaut ◽  
Pierre Steinmetz
Keyword(s):  
Mechanical Properties ◽  
Melting Point ◽  
Molten Glass ◽  
Energy Production ◽  
Creep Properties ◽  
Refractory Alloys ◽  
Industrial Use ◽  
Kinetics Of ◽  
Selection Of

For energy production and also for the glass industry, finding new refractory alloys which could permit to increase the process temperatures to 1200°C or more is a permanent challenge. Chromium base alloys can be good candidates, considering the melting point of Cr itself, and also its low corrosion rate in molten glass. Two families of alloys have been studied for this purpose, Cr-Mo-W and Cr-Ta-X alloys (X= Mo, Si..). A finer selection of compositions has been done, to optimize their chemical and mechanical properties. Kinetics of HT oxidation by air, of corrosion by molten glass and also creep properties of several alloys have been measured up to 1250°C. The results obtained with the best alloys (Cr-Ta base) give positive indications as regards the possibility of their industrial use.

scholarly journals Synthesis and Polymerization Kinetics of Rigid Tricyanate Ester

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1686
Author(s):  
Andrey Galukhin ◽  
Roman Nosov ◽  
Ilya Nikolaev ◽  
Elena Melnikova ◽  
Daut Islamov ◽  
...  
Keyword(s):  
Kinetic Analysis ◽  
Single Step ◽  
Polymerization Kinetics ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
Diffusion Controlled ◽  
Polymerization Product ◽  
The One ◽  
Kinetics Of

A new rigid tricyanate ester consisting of seven conjugated aromatic units is synthesized, and its structure is confirmed by X-ray analysis. This ester undergoes thermally stimulated polymerization in a liquid state. Conventional and temperature-modulated differential scanning calorimetry techniques are employed to study the polymerization kinetics. A transition of polymerization from a kinetic- to a diffusion-controlled regime is detected. Kinetic analysis is performed by combining isoconversional and model-based computations. It demonstrates that polymerization in the kinetically controlled regime of the present monomer can be described as a quasi-single-step, auto-catalytic, process. The diffusion contribution is parameterized by the Fournier model. Kinetic analysis is complemented by characterization of thermal properties of the corresponding polymerization product by means of thermogravimetric and thermomechanical analyses. Overall, the obtained experimental results are consistent with our hypothesis about the relation between the rigidity and functionality of the cyanate ester monomer, on the one hand, and its reactivity and glass transition temperature of the corresponding polymer, on the other hand.

On the use of Ozawa/Flynn/Wall method to determine aging activation energy for elastomers

2021 ◽  
pp. 009524432110203
Author(s):  
Sudhir Bafna
Keyword(s):  
Mechanical Properties ◽  
Activation Energy ◽  
Weight Loss ◽  
Oxygen Consumption ◽  
Dwell Time ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Degradation Mechanism ◽  
Kinetics Of ◽  
Wall Method

It is often necessary to assess the effect of aging at room temperature over years/decades for hardware containing elastomeric components such as oring seals or shock isolators. In order to determine this effect, accelerated oven aging at elevated temperatures is pursued. When doing so, it is vital that the degradation mechanism still be representative of that prevalent at room temperature. This places an upper limit on the elevated oven temperature, which in turn, increases the dwell time in the oven. As a result, the oven dwell time can run into months, if not years, something that is not realistically feasible due to resource/schedule constraints in industry. Measuring activation energy (Ea) of elastomer aging by test methods such as tensile strength or elongation, compression set, modulus, oxygen consumption, etc. is expensive and time consuming. Use of kinetics of weight loss by ThermoGravimetric Analysis (TGA) using the Ozawa/Flynn/Wall method per ASTM E1641 is an attractive option (especially due to the availability of commercial instrumentation with software to make the required measurements and calculations) and is widely used. There is no fundamental scientific reason why the kinetics of weight loss at elevated temperatures should correlate to the kinetics of loss of mechanical properties over years/decades at room temperature. Ea obtained by high temperature weight loss is almost always significantly higher than that obtained by measurements of mechanical properties or oxygen consumption over extended periods at much lower temperatures. In this paper, data on five different elastomer types (butyl, nitrile, EPDM, polychloroprene and fluorocarbon) are presented to prove that point. Thus, use of Ea determined by weight loss by TGA tends to give unrealistically high values, which in turn, will lead to incorrectly high predictions of storage life at room temperature.

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