Towards an Application of PBD Principles for Innovative Recentering Beam-to-Column Connections

2013 ◽  
Vol 716 ◽  
pp. 569-574
Author(s):  
Jong Wan Hu ◽  
Ga Lam Choi
Keyword(s):  
Numerical Experiments ◽  
Three Dimensional ◽  
Low Carbon Steel ◽  
Element Model ◽  
Unintended Consequence ◽  
Steel Beams ◽  
Global Behavior ◽  
Low Carbon ◽  
Physical Testing ◽  
Composite Connections

An unintended consequence is that some freedom in the introduction of innovative composite connections has been removed. The innovative aspects of this connection are in the use of partial restraint connections between steel beams and concrete-filled tube columns that utilize a combination of low-carbon steel and shape memory alloy components. A refined finite element model with sophisticated three dimensional solid elements was developed to conduct numerical experiments on the proposed joints to obtain the global behavior of the connection and develop simplified models. The paper argues that careful analytical studies can replace the requirement for physical testing present in current steel codes.

Laser Forming for Flexible Fabrication

2000 ◽  
Vol 16 (02) ◽  
pp. 97-109
Author(s):  
Koichi Masubuchi ◽  
Jerry E. Jones
Keyword(s):  
Three Dimensional ◽  
Low Carbon Steel ◽  
High Strength Steels ◽  
Cost Benefit ◽  
Network Models ◽  
High Strength ◽  
Laser Forming ◽  
Low Carbon ◽  
Flat Plates ◽  
Neural Network Models

A 36-month program supported by the Defense Advanced Research Projects Agency (DARPA) was conducted to demonstrate the feasibility to predictably laser form a variety of ferrous and non-ferrous metals of different thickness. Laser forming provides a method of producing complex shapes in sheet, plate, and tubing without the use of tooling, molds, or dies. By heating a localized area with a laser beam, it is possible to create stress states that result in predictable deformation. This research program has developed, refined and demonstrated constitutive and empirical, and neural network models to predict deformation as a function of critical parametric variables and established an understanding of the effect of laser forming on some metallurgical properties of materials. The program was organized into two, time-phased tasks. The first task involved forming flat plates to one-dimensional (I -D) shapes, such as, hinge bends in various materials including low-carbon steel, high-strength steels, nickel-based super alloys, and aluminum alloys. The second task expanded the work conducted in the first task to investigate three-dimensional (3-D) configurations. The models were updated, 3-D specimens fabricated and evaluated, and cost benefit analyses were performed.

The Effect of Severe Plastic Deformation on the Brittle-Ductile Transition in Low Carbon Steel

2009 ◽  
Vol 633-634 ◽  
pp. 471-480
Author(s):  
Masaki Tanaka ◽  
Kenji Higashida ◽  
Tomotsugu Shimokawa
Keyword(s):  
Fracture Toughness ◽  
Carbon Steel ◽  
Grain Boundaries ◽  
Three Dimensional ◽  
Low Carbon Steel ◽  
Dislocation Dynamics ◽  
Strain Rates ◽  
Low Carbon ◽  
Dislocation Source ◽  
Brittle Ductile Transition

Brittle-ductile transition (BDT) behaviour was investigated in low carbon steel deformed by an accumulative roll-bonding (ARB) process. The temperature dependence of its fracture toughness was measured by conducting four-point bending tests at various temperatures and strain rates. The fracture toughness increased while the BDT temperature decreased in the specimens deformed by the ARB process. Arrhenius plots between the BDT temperatures and the strain rates indicated that the activation energy for the controlling process of the BDT was not changed by the deformation with the ARB process. It was deduced that the decrease in the BDT temperature by grain refining was not due to the increase in the dislocation mobility controlled by short-range barriers. Quasi-three-dimensional simulations of dislocation dynamics, taking into account of crack tip shielding due to dislocations, were performed to investigate the effect of a dislocation source spacing along a crack front on the BDT. The simulation indicated that the BDT temperature is decreased with decreasing in the dislocation source spacing. Molecular dynamics simulations revealed that moving dislocations were impinged against grain boundaries and were reemitted from there with increasing strain. It indicates that grain boundaries can be new sources in ultra-fine grained materials, which increases toughness at low temperatures.

Impeller Finite Element Analysis of Extractable Explosion-Proof Contra-Rotating Axial Fan for Mine Local Ventilation FBDC

2012 ◽  
Vol 605-607 ◽  
pp. 1372-1376
Author(s):  
Qiu Dong He ◽  
Wen Qi Yu ◽  
Shu Fen Xiao
Keyword(s):  
Finite Element ◽  
Static Pressure ◽  
Three Dimensional ◽  
Low Carbon Steel ◽  
Sound Level ◽  
Low Carbon ◽  
Axial Fan ◽  
Element Analysis ◽  
Local Ventilation ◽  
Three Dimensional Finite Element

To improve the impeller safety and reliability of extractable explosion-proof contra-rotating axial fan for mine local ventilation, Extractable Fan FBDC№9.0/2×30 was taken as the research object, and an approximate three-dimensional finite element computation model was built by using ANSYS software. The stress and displacement were calculated, too. By testing, the fan works stably. The air quantity is 655-978 m3/min, total pressure, 3443-412Pa, static pressure, 3314-118Pa. And the highest static pressure efficiency is up to 70.35%, A-weight Specific Sound Level is 17.5dB. Furthermore, the intension and stiffness of the impeller meet requirements. Sample test and field using show that the computation and the model of this impeller are right. Through reasonable design, the impeller of contra-rotating axial fan with equally-thick circular arc blade profile and ordinary hot-rolling low-carbon steel blades has the intension and the stiffness which meets demands, and the air performance reaches higher level.

scholarly journals Three-dimensional Observation of Ferrite Plate in Low Carbon Steel Weld

2005 ◽  
Vol 45 (5) ◽  
pp. 756-762 ◽  
Author(s):  
M. ENOMOTO ◽  
K. M. WU ◽  
Y. INAGAWA ◽  
T. MURAKAMI ◽  
S. NANBA
Keyword(s):  
Carbon Steel ◽  
Three Dimensional ◽  
Low Carbon Steel ◽  
Steel Weld ◽  
Low Carbon ◽  
Ferrite Plate
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