Articolele autorului Cristian Spanu
Link la profilul stiintific al lui Cristian Spanu

Trajectory Simulation and Material Removal Rate for Double Side Grinding of Advanced Ceramics with Diamond Wheels

A computerized kinematical model for double sided fine grinding accounting for piece rotation inside the workpiece carrier was developed. Simulated trajectories for random points located on the end faces of the workpiece, both in a fixed global coordinate system and in each wheel's rotating coordinate system, were predicted. Experiments using different grinding kinematics and coolant conditions were carried out. A strong correlation was found between

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Double side grinding of advanced ceramics with diamond wheels
Electrolytic In-Process Dressing (ELID) Assisted

A double side grinding process assisted by an electrolytic in-process dressing (ELID) technique for finishing advanced ceramics components using metal bonded fine diamond wheels was designed, operated, and optimized. The goals of this research focused on improving the process efficiency, the quality of the produced surface, and the tool life. Implementing and operating industrially a highly productive, economical, easy-to-automate and ecological

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Bonded Versus Loose Diamond Abrasion

Surface finish, material removal rate, and geometrical characterization of the surface are assessed and compared after machining identical aloxide (Al2O3) ceramic workpieces with bond diamond (double side grinding operation), and loose diamond (lapping operation), in comparable conditions of load per grain and average grain size. The results showed that bonded abrasive grinding produces comparable surface quality and higher material removal rates

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Electrolytic In Process Dressing (ELID) Applied To Double Side Grinding of Ceramic Materials

The objective of the present work is to design, optimize, and validate an electrolytic in-process dressing (ELID)-assisted double side grinding process for finishing advanced ceramic components. To attain this objective, an original ELID double side grinding system was designed, fabricated, and operated at the Precision Micro-Machining Center of The University of Toledo, Ohio. The ELID technique was selected from among other options to assure the

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Biomechanics of the knee joint in deep flexion: A prelude to a total knee replacement that allows for maximum flexion

A two-dimensional anatomically based mathematical model of the human knee joint was developed to understand its biomechanics in deep flexion. The model was used to determine the internal knee loads as it simulates isometric quadriceps and hamstring co-contractions at different flexion angles during deep squat. It was found that in order to achieve deep flexion, large muscle forces are required, resulting in large tibio-femoral contact forces. In

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Double Side Grinding of Alumina Ceramics Using Diamond Wheels

Acest proiect studiaza din punct de vedere technologic operatia de rectificare plana bilaterala aplicata fetelor paralele ale unor piese cilindrice din alumina utilizind doua pietre abrazive cu diamant. Materialele ceramice sunt atractive pentru multiple aplicatii datorita duritatii, rezistentei la compresiune, rezistentei termice, proprietatilor magnetice superioare, permeabilitatii magnetice si fragilitatii care le caracterizeaza. Un experiment

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Experimental Comparison Between Two- And Three-Body-Abrasion Processes As Applied To Alumina Ceramics

Rata de eliminare a materialului, gradul de finisare al suprafetei precum si caracteristicile geometrice ale suprafetei, au fost parametrii evaluati si comparati dupa prelucrarea prin rectificare si lepuire ale unor piese identice din Al2O3 in conditii similare de forta pe graunte si marime medie a grauntelui abraziv. Scopul este de a fundamenta decizia de a inlocui lepuirea cu rectificarea, care este mai productiva, mai economica si nepoluanta.

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Role of the cruciate ligaments in deep squat

Scopul lucrarii este sa determine rolul ligamentelor cruciate in timpul flexarii genunchiului pina la 150 grade. Un model matematico-anatomic bi-dimensional a fost dezvoltat. Simularea a fost condusa pentru simularea contractiilor isometrice ale quadricepsului asociate cu co-contractia hamstring-ului (scuze, nu cunosc traducerea in lb. romana) pentru diferite pozitii in timpul flexarii genunchiului. FIbrele anterioare si posterioare ale ligamentului

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“Determination of the Knee Joint Internal Loads During Deep Squat

The objective of the present work is to determine the internal loads inside the knee joint during a deep squat while the knee is maximally flexed, up to 150 degrees of knee flexion. A two-dimensional anatomical mathematical model of the human knee joint was developed for this purpose. To collect model input data, X-rays were first obtained to determine the mathematical representation of the tibial and femoral articular surfaces. An X-ray stand was

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