Search results for "Steel"

Fatigue Design of Cruciform Joints including V-notch Effect at the Weld Toe

2014

Abstract The present paper proposes a new and more accurate fatigue life prediction model for fillet welded joints in steel subjected to constant amplitude loading. With the traditional fracture mechanics approach, the greatest difficulty when computing the fatigue life of a welded detail is to determine the initial crack size a0. The classical way to determine the stress intensity factor K (SIF) is by using the following formula Where σ is the applied stress, a is the crack size and g(a/T) the geometrical correction factor which has been determined by Gurney function or similar solutions. This approach is not accurate for short crack because of the singular V-notch behaviour close to the c…

Effect of process parameters in Linear Friction Welding Processes of Steels

2011

An innovative moment resisting steel connection: optimal design formulations, practical applications and experimental tests

2023

This thesis concerns the study of an innovative moment resisting connection device to be adopted in the so-called moment resisting steel frames. Following previous seismic events, such as Northridge in 1994, many steel structures characterized by welded connections between beams and columns experienced extended damages and diffused brittle failures, making the facilities unserviceable and economically disadvantageous to repair. The answers to this problem is represented by a large number of studies, where several proposals for different devices, as well as special technical solutions, are available. However, the main idea developed among all the proposals is represented by the identificatio…

Numerical validation of LRPH behaviour by FEM analysis

2019

LRPH connection is a special steel device mainly usable to join beam elements of plane or spatial steel frames. It is identified as Limited Resistance Rigid Perfectly Plastic Hinge and it is covered by patent n. 102017000088597 at the Italian Ministry of Economic Development and identified in the International Patent System with the number PCT/IB2018/055766. The fundamental innovations of this device are the mutual independence of their own resistance and stiffness features and the respect of assigned constraints related to the elastic and limit behavior of the joined elements. Within the frame structural scheme, the device plays the role of a rigid perfectly plastic hinge, and it is consti…

Design and manufacturing feasibility of ITER TBM Frame and Dummy TBMs

2016

Abstract The operation and test of mock-ups of tritium breeding blankets relevant for a future commercial reactor is one of the goals of the ITER machine. To accomplish this goal, mock-ups of breeding blankets, called Test Blanket Modules (TBMs), are installed in three ITER equatorial ports. Each TBM and the associated shield form a TBM-set that is mechanically attached to a steel frame called TBM Frame. A Frame and two TBM-Sets form a TBM Port Plug (TBM PP). The ITER Organization is responsible for the design and manufacture of the TBM Frames and of the Dummy TBMs that could replace the TBM-sets in case they were not available. This paper describes the recent results of the design supporti…

Flexural behavior of external beam-column reinforced concrete assemblages externally strengthened with steel cages

2016

In this paper, an experimental study referring to the flexural behavior of full-scale external beam-column joints externally strengthened with steel angles and strips and subjected to cyclic reversal loading is presented. One control specimen and five other specimens having the same characteristics as the control specimen but strengthened with steel angles and strips along beams and columns, and characterized by different configurations of strengthening in the critical regions, were tested. The control specimen was designed with a weak column and strong beam to reproduce the most common cases of old frame structures in the Mediterranean area, which were designed only for gravity loads and a…

Identification of optimal device combinations for the chimney endovascular aneurysm repair technique within the PERICLES registry

2018

Abstract Objective The ideal stent combination for chimney endovascular aneurysm repair remains undetermined. Therefore, we sought to identify optimal aortic and chimney stent combinations that are associated with the best outcomes by analyzing the worldwide collected experience in the PERformance of chImney technique for the treatment of Complex aortic pathoLogiES (PERICLES) registry. Methods The PERICLES registry was reviewed for patients with pararenal aortic disease electively treated from 2008 to 2014. Eleven different aortic devices were identified with three distinct subgroups: group A (n = 224), nitinol/polyester; group B (n = 105), stainless steel/polyester; and group C (n = 69), n…

MMP-2, MMP-9, and iNOS Expression in Human Dental Pulp Subjected to Orthodontic Traction

2009

Abstract Objective: To test the hypothesis that some metalloproteinases (MMP-2, MMP-9) and inducible nitric oxide synthetase (iNOS) enzymes in dental pulp samples do not vary when subjected to orthodontic treatment. Materials and Methods: Human dental pulps were taken from male and female patients (N=10; age 10–14 years). A straight wire technique was used with nickel-titanium or steel archwires. The increase of pressure applied on teeth was gradual. Five patients were subjected to premolar extractions after 14 months of treatment and one after 24 months. Samples were Bouin-fixed, paraffin-embedded, and afterwards processed for immunohistochemistry using anti-MMP-2, anti-MMP-9, and anti-iNO…

Toxicity of used orthodontic archwires assessed by three-dimensional cell culture

2006

The aim of the present study was to determine whether used orthodontic wires made of different materials cause toxicity and loss of viability on three-dimensional (3D) cell cultures. Three types of orthodontic wires, stainless steel, Nitinol, and TMA (n = 9) which had been used clinically in fixed appliances for a period of 1 month, were retrieved at random from five patients. Both upper and lower archwires were collected and subjected to two different protocols: to assess toxicity, two pieces of each wire were placed on 3D cell cultures (reconstituted human epithelium); to investigate the possibility of cell damage, the 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyl tetrazolium bromide (MTT) ass…

Impedance characterization of the electrochemical environment under a polymer film artificially delaminated

2008

International audience; Knowledge of the electrical conductivity of the zone under a delaminated paint film is one necessary input parameter for the simulation of electrochemically driven underpaint corrosion. In this work, a microelectrode array system has been developed, tested, and applied to measure the spatial distribution of resistivity in the delaminated zone along the metal/polymer interface. The experimental device consists of a linear array of six 100 m diameter stainless steel microelectrodes (100 m in diameter) embedded in a steel substrate. A polymer coatingwas applied and an artificial "delaminated zone"was created using the laser-induced decohesion technique. The electrochemi…