Search results for " Simulation"
showing 10 items of 4034 documents
Forces and deformations of the abdominal wall—A mechanical and geometrical approach to the linea alba
2011
Force-elongation responses of the human abdominal wall in the linea alba region were determined by tensile tests in which the linea alba was seen to exhibit a nonlinear elastic, anisotropic behavior as is frequently observed in soft biological tissues. In addition, the geometry of the abdominal wall was determined, based on MRI data. The geometry can be specified by principal radii of curvature in longitudinal of approximately 470 mm and in the transverse direction of about 200 mm. The determined radii agree with values found in other studies. Mechanical stresses, deformations and abdominal pressures for load cases above 6% elongation can be related using Laplace's formula and our constitut…
Proteins in amorphous saccharide matrices: Structural and dynamical insights on bioprotection
2013
Bioprotection by sugars, and in particular trehalose peculiarity, is a relevant topic due to the implications in several fields. The underlying mechanisms are not yet clearly elucidated, and remain the focus of current investigations. Here we revisit data obtained at our lab on binary sugar/water and ternary protein/sugar/water systems, in wide ranges of water content and temperature, in the light of the current literature. The data here discussed come from complementary techniques (Infrared Spectroscopy, Molecular Dynamics simulations, Small Angle X-ray Scattering and Calorimetry), which provided a consistent description of the bioprotection by sugars from the atomistic to the macroscopic …
Design of a reactor operating in supercritical water conditions using CFD simulations. Examples of synthesized nanomaterials
2011
International audience; Direct information about fluids under supercritical water conditions is unfeasible due to the engineering restrictions at high pressure and high temperature. Numerical investigations based on computational fluid dynamics (CFD) calculations are widely used in order to get extensive information on the fluid behavior, particularly to help the design of a new reactor. This paper presents the numerical investigations performed on an original supercritical water device, especially in the level of the reactor. CFD calculations allow to design and optimize the present reactor described in this study. Currently, this process produces some nanometric oxide powders in continuou…
Electrical conductance of carbon nanotubes with misaligned ends
2013
During a manufacturing process, when a straight carbon nanotube is placed on a substrate, e.g., production of transistors, its two ends are often misaligned. In this study, we investigate the effects of multiwall carbon nanotubes’ (MWCNTs) outer diameter and chirality on the change in conductance due to misalignment of the two ends. The length of the studied MWCNTs was 120 nm, while the diameters ranged between 4 and 7 nm. A mixed finite element-tight-binding approach was carefully designed to realize reduction in computational time by orders of magnitude in calculating the deformation-induced changes in the electrical transport properties of the nanotubes. Numerical results suggest that ar…
Fatigue crack initiation and subsequent crack growth in fillet welded steel joints
2019
Abstract The fatigue damage evolution in fillet welded steel joints where cracks are emanating from the weld toe is investigated. Based on existing experimental data for as-welded joints including crack depth measurements of the early crack growth it is proposed to make a distinction between the crack initiation phase and the subsequent crack growth phase. The welded detail in question is an F class detail with plate thickness 25 mm made of medium strength carbon steel. It is found that the crack initiation phase defined at a crack depth of 0.1 mm is close to 25% of the fatigue life even at a relatively high constant stress range of 150 MPa. At lower stress ranges it is concluded that the i…
Comparison of the friction and wear properties of titanium and oxidised titanium in dry sliding against sintered high speed steel HS18-0-1 and agains…
2005
Abstract The paper presents the results of conformal pin-on-disc tribological tests concerning the hard oxidised zone, α-Ti(O), created at the surface of a titanium specimens sliding against the sintered and hardened up to 850 HV30, Grade T1 high speed steel (HS18-0-1) counterspecimens. Comparison with the results obtained for the tests performed against hardened up to 620 HV30 C45 carbon steel counterspecimens has been done. Testing was carried out at room temperature and at unlubricated conditions. After tests the structures and compositions of the worn surfaces and wear debris were a subject of LOM, SEM observations and X-ray microanalyses. In comparison with the baseline—the Ti/T1 HSS c…
The role of coatings in controlling the cutting process when turning with coated indexable inserts
1998
Abstract This paper is concerned with the variations in the specific cutting pressure and the tool–chip interface temperature that occur when machining a medium carbon steel and an austenitic stainless steel with TiC-, TiC/TiN- and TiC/Al2O3/TiN- coated inserts. Extensive experimental studies involving the cutting force and the interface temperature were performed. A standard thermocouple embedded in the workpiece was used to determine the cutting temperature. Two new parameters were introduced in order to compare both the mechanical and thermal loadings of the tool–chip contact for coated flat-faced and grooved inserts. Some optimal coating structures for high speed machining of these stee…
Friction and wear properties of titanium and oxidised titanium in dry sliding against hardened C45 steel
2004
Abstract The aim of the paper is to present the results of conformal pin-on-disc tribological tests concerning the hard oxidised zone created in superficial layer of a titanium specimen sliding against the hardened to a hardness of 690 HV carbon C45 steel counterspecimen. Tribological testing was carried out at room temperature and at unlubricated conditions. After tests the structures and chemical compositions of the wear debris and worn surfaces were a subject of SEM and X-ray investigations. In comparison with the baseline the technical quality titanium/C45 steel couple, the wear and lifetime performance of the oxidised titanium/steel C45couple was markedly superior. Dominant wear debris…
Frontiers in molecular simulation of solvated ions, molecules and interfaces.
2020
This themed collection is a collection of articles on frontiers in molecular simulation of solvated ions, molecules and interfaces.
Laser-induced damage in cold-sprayed composite coatings
2011
International audience; Ag-Ni composite coatings were achieved using the cold spray process. In this work, two blends were sprayed to lead to coatings with different mechanical properties, which corresponded to either a fine or a coarse microstructure. These coatings were studied using SEM and X-ray microtomography (XMT) to determine the best coating quality through characterization of particle-to-particle bonding. The fine microstructure showed better properties than the coarse microstructure. To avoid time-consuming characterization techniques such as SEM and XMT, an innovative laser characterization test was developed. The principle of this test is based on the thermal shock-induced by a…