Experimental and Analytical Studies on Steel-Reinforced Concrete Composite Members with Bonded Prestressed CFRP tendon under Eccentric Tension

This paper reported the very earliest experimental and analytical studies on the bonded Prestressed CFRP tendon enhanced Steel Reinforced Concrete (PSRC) members under eccentric tensile loads. Eight PSRC members were tested under monotonic eccentric tensile loading, and three Steel Reinforced Concrete (SRC) members were simultaneously tested for comparison. The load-deflection relationship, the strain distributions as well as the crack propagation and fracture of concrete were investigated experimentally and analytically. The results demonstrated an improvement in the eccentric tensile capacity of PSRC members upon increasing both the steel and reinforcement ratios, or by reducing the prestress eccentricity. The results also suggested that an enhancement in the level of prestressing increased can decrease the crack propagation and lateral deflection. Moreover, the validity of the plane-section assumption was confirmed. An analytical model was proposed for predicting the elastic bending capacity of the PSRC members based on the experimental results. The study provided an in-depth understanding of the structural behaviour of PSRC members with bonded prestressed CFRP tendon under the eccentric tension underpinned by the elaborate experimental design and practical analytical model

FED-A, an advanced performance FED based on low safety factor and current drive

This document is one of four describing studies performed in FY 1982 within the context of the Fusion Engineering Device (FED) Program for the Office of Fusion Energy, U.S. Department of Energy. The documents are: 1. FED Baseline Engineering Studies (ORNL/FEDC-82/2), 2. FED-A, An Advanced Performance FED Based on Low Safety Factor and Current Drive (this document), 3. FED-R, A Fusion Device Utilizing Resistive Magnets (ORNL/FEDC-82/1), and 4. Technology Demonstration Facility TDF. These studies extend the FED Baseline concept of FY 1981 and develop innovative and alternative concepts for the FED. The FED-A study project was carried out as part of the Innovative and Alternative Tokamak FED studies, under the direction of P. H. Rutherford, which were part of the national FED program during FY 1982. The studies were performed jointly by senior scientists in the magnetic fusion community and the staff of the Fusion Engineering Design Center (FEDC). Y-K. M. Peng of the FEDC, on assignment from Oak Ridge National Laboratory, served as the design manager

HIGH PERFORMANCE PLASMAS ON THE NATIONAL SPHERICAL TORUS EXPERIMENT

The National Spherical Torus Experiment has produced toroidal plasmas at low aspect ratio (A = R/a = 0.86d0.68m - 1.3, where R is the major radius and a is the minor radius of the torus) with plasma currents of 1.4MA. The rapid development of the machine has led to very exciting physics results during the first full year of physics operation. Pulse lengths in excess of 0.5s have been obtained with inductive current drive. Up to 4MW of High Harmonic Fast Wave (HHFW) heating power has been applied with 6MW planned. Using only 2MW of HHFW heating power clear evidence of electron heating is sden with HHFW, as observed by the multi point Thomson scattering diagnostic. A non-inductive current drive concept known as Coaxial Helicity Injection (CHI) has driven 260kA of toroidal current. Neutral beam heating power of 5MW has been injected. Plasmas with PI ( =2p0/B2 = a measure of magnetic confinement efficiency) of 22% have been achieved, as calculated using the EFIT equilibrium reconstruction code. P limiting phenomena have been observed, and the maximum p, scales with I&z& High frequency (>MHz) magnetic fluctuations have been observed. H-mode plasmas are observed with confinement times of > 100ms. Beam heated plasmas show energy confinement times in excess of those predicted by empirical scaling expressions. Ion temperatures in excess of 2.OkeV have been measured, and power balance suggests that the power loss from the ions to the electrons may exceed the calculated classical input power to the ions

A feasibility study for the spherical torus experiment

Oak Ridge National Laboratory (ORNL) proposes to build the Spherical Torus Experiment (STX), a very low aspect ratio toroidal confinement device. This proposal concentrates on tokamak operation of the experiment; however, it can in principle be operated as a pinch or reversed-field pinch as well. As a tokamak, the spherical torus confines a plasma that is characterized by high toroidal beta, low poloidal beta, large natural elongation, high plasma current for a given edge q, and strong paramagnetism. These features combine to offer the possibility of a compact, low-field fusion device. The figure below shows that when compared to a conventional tokamak the spherical torus represents a major change in geometry. The primary goals of the experiment will be to demonstrate a capability for high beta (20%) in the first stability regime, to extend our knowledge of tokamak confinement scaling, and to test oscillating-field current drive. The experiment will operate in the high-beta, collisionless regime, which is achieved in STX at low temperatures because of the geometry. At a minimum, operation of STX will help to resolve fundamental questions regarding the scaling of beta and confinement in tokamaks. Complete success in this program would have a significant impact on toroidal fusion research in that it would demonstrate solutions to the problems of beta and steady-state operation in the tokamak. The proposed device has a major radius of 0.45 m, a toroidai field of 0.5 T, a plasma current of 900 kA, and heating by neutral beam injection. We estimate 30 months for design, construction, and assembly. The budget estimate, including contingency and escalation, is $6.8 million

FED-A, an advanced performance FED based on low safety factor and current drive

This document is one of four describing studies performed in FY 1982 within the context of the Fusion Engineering Device (FED) Program for the Office of Fusion Energy, U.S. Department of Energy. The documents are: 1. FED Baseline Engineering Studies (ORNL/FEDC-82/2), 2. FED-A, An Advanced Performance FED Based on Low Safety Factor and Current Drive (this document), 3. FED-R, A Fusion Device Utilizing Resistive Magnets (ORNL/FEDC-82/1), and 4. Technology Demonstration Facility TDF. These studies extend the FED Baseline concept of FY 1981 and develop innovative and alternative concepts for the FED. The FED-A study project was carried out as part of the Innovative and Alternative Tokamak FED studies, under the direction of P. H. Rutherford, which were part of the national FED program during FY 1982. The studies were performed jointly by senior scientists in the magnetic fusion community and the staff of the Fusion Engineering Design Center (FEDC). Y-K. M. Peng of the FEDC, on assignment from Oak Ridge National Laboratory, served as the design manager