Search results for "Elastic"
showing 10 items of 2162 documents
Seismic shakedown design of frames based on a probabilistic approach
2014
The present study concerns the optimal design of elastic perfectly plastic structures subjected to a combination of fixed and seismic loads. In particular, plane frames are considered and suitable measures of the beam element cross sections are chosen as design variables. The optimal design is required to behave in a purely elastic manner when subjected just to the fixed load and to have the capability to eventually shakedown when simultaneously subjected to fixed and seismic loads. Due to the natural uncertainness related to the definition of the seismic load history, a new probabilistic approach is proposed, consisting into two subsequent search steps. At first a suitably chosen large num…
On the Post-Elastic Behavior of LRPH Connections
2019
The paper concerns the study of the post-elastic behavior of a recently proposed innovative device, named Limited Resistance Rigid Perfectly Plastic Hinge (LRPH). In particular, LRPH is a steel device of finite length realizing a moment connection between beam elements of a steel frame; it is designed in order to possess two main and independent requirements: its bending moment resistance must be suitably lower than the one of the connected beam element and its overall bending stiffness must be equal to that of the connected beam element characterized by the same length. In order to make the proposed device reliable, LRPH must be capable of realizing a full plastic hinge for the assigned be…
Influence of formalin fixation on the biomechanical properties of human diaphyseal bone.
2010
Owing to the lack of fresh human bones, formalin-fixed specimens are frequently used in biomechanical testing. However, formalin fixation is assumed to affect the biomechanical properties of bone. The aim of this study was to compare axial and torsional stiffness and bone mineral density in fresh and embalmed human bones. The subtrochanteric regions of 12 pairs of fresh human femora were randomised into two groups for paired comparison. After bone mineral density measurement, one group was preserved in 4% formalin. After 6 weeks, bone mineral density was remeasured and each specimen underwent axial and torsional loading. The formalin group showed significant higher stiffness values for tors…
Sind winkelstabile Plattensysteme mit elastischen Eigenschaften für die Stabilisierung der Oberarmkopffraktur vorteilhaft? / Eine in-vitro biomechani…
2004
AbstractWinkelstabile Platten werden mit zunehmender Häufigkeit zur Stabilisierung von Oberarmkopfbrüchen verwendet. Rigide Implantate führen bei osteoporotischen Knochenverhältnissen u. U. aber häufiger zum Versagen. Um den Effekt der Implantatelastizität zu beurteilen wurden in einer in-vitro Studie die biomechanischen Eigenschaften eines rigiden und eines elastischen winkelstabilen Plattensystems vergleichend analysiert. An 8 Humeruspaaren wurde eine instabile subkapitale Fraktur simuliert. Die Proben wurden axial- und torsions-belastet. Analysiert wurden die Steifigkeit, das Setzverhalten unter Dauerlast und die Versagensbelastung.Das elastische Plattensystem kennzeichnete sich durch ei…
Photoelastic analysis of conventional and locking system for treatment of mandibular angle fractures with a single plate
2021
Made available in DSpace on 2021-06-25T10:28:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-04-01 Background: This photoelastic analysis evaluated stress distribution in different osteosynthesis systems, conventional and locking, used for treatment of mandibular angle fractures with a single plate. Material and Methods: Angle fractures were simulated in mandibles made of photoelastic resin. Following Champy’s method, plate osteosynthesis was performed. The samples were divided into five groups: Group 1, non-fractured mandible; Group 2, two screws were installed in each segment using a conventional system; Group 3, two screws were installed in each segment using a locking system; …
"Table 2" of "Transverse momentum of J / psi produced in p Cu, p U, O-16 Cu, O-16 U and S-32 U collisions at 200-GeV per nucleon."
1991
CONTINUUM MUONS ORIGINATE MAINLY FROM VECTOR MESON DECAYS, SEMI-LEPTONIC DECAYS OF D DBAR PAIRS AND FROM DRELL-YAN MECHANISM.
Rheological characterization of chitosan matrices: Influence of biopolymer concentration
2007
Viscoelastic properties of chitosan (CH), chitosan-poly(ethylene glycol) 400 (CH-PEG), and chitosan-poly(ethylene glycol) 400 with glyoxal as crosslinking agent (CH-PEG-Gly) systems were studied to analyze the effect of chitosan concentration (from 0.83 to 1.67%). Dynamic moduli increase as chitosan concentration increases for all systems. For CH and CH-PEG systems the loss modulus (G″) is greater than the storage modulus (G′) with predominance of the viscous over the elastic behavior. This corresponds to the characteristic behavior of solutions (nonstructured systems). The presence of PEG 400 induces a complementary reinforcement of the mechanical properties of the system. Except for the l…
DIMENSIONAL STABILITY OF REINFORCED MATRICES.
1983
Particulate fillers are often used to improve the dimensional stability of polymeric items obtained through processing techniques such as injection molding, deep drawing, hot stamping, etc. In these operations the material undergoes large multiaxial deformations which result in molecular orientation and remain as frozen-in stresses during cooling of the material. Once the formed objects are exposed to sufficiently high temperatures, various degrees of spring-back take place and subsequent changes in shape and dimension occur (1).
Displacement measurement through DIC and DSPI techniques in cold-expanded holes
2008
In this paper, the displacement field induced by the split-sleeve cold expansion of holes was measured using both digital image correlation (DIC) and digital speckle pattern interferometry (DSPI) techniques. Thus, the experimental results, which were evaluated on the inlet surface of a 6082-T6 aluminium plate, were compared with those from theoretical prediction. DIC provided accurate measurements up to the elastic-plastic boundary, whereas the DSPI technique highlighted the changes of displacement in the elastic domain. Prediction of the displacement based on the existing analytical model agreed with the experimental results achieved with both techniques. Possible explanations for the diff…
"Table 26" of "Measurement of the Collins and Sivers asymmetries on transversely polarised protons"
2007
The COLLINS asymmetry for negatively charged hadrons as a function of W for X < 0.032.