Numerical Modeling of Composite Concrete Walls

2008 ◽  
Author(s):  
Eytan Kochavi ◽  
Yosef Kivity ◽  
Ido Anteby ◽  
Oren Sadot ◽  
Gabi Ben-Dor
Keyword(s):  
University Of California ◽  
Test Results ◽  
Dynamic Tests ◽  
Material Models ◽  
Concrete Walls ◽  
Beer Sheva ◽  
Simulation Results ◽  
The University ◽  
Development Center ◽  
Good Agreement

Dynamic tests of three reinforced concrete samples and six Dynablok samples were performed in the blast simulator facility at the University of California San-Diego (UCSD). The purpose of these tests was to evaluate the performance of a novel protective wall design. These tests were numerically simulated at the Protective Technologies Research and Development Center (PTR&DC) of the Ben-Gurion University (BGU) in Beer-Sheva, Israel. The simulations were carried out using two commercial hydro-codes: LS-Dyna and Dytran. The purpose of these simulations was to calibrate the parameters of the material models available in the above codes. Once calibrated, the simulation results showed good agreement with the test results for largely deflected yet moderately damaged specimens.

scholarly journals A Successful Educational Collaboration between Scientists and Educators: Microscopic Explorations

2003 ◽  
Vol 2 (1) ◽  
pp. 25-28 ◽  
Author(s):  
Lincoln Bergman ◽  
Caroline Schooley
Keyword(s):  
Low Cost ◽  
Lessons Learned ◽  
University Of California ◽  
Outreach Program ◽  
Public Science ◽  
The Public ◽  
Educational Collaboration ◽  
The University ◽  
Lawrence Hall Of Science ◽  
Development Center

The teacher's guide, Microscopic Explorations: A GEMS Festival Guide ( Brady and Willard, 1998 ), is the result of a partnership between Great Explorations in Math and Science (GEMS), a program of the Lawrence Hall of Science (LHS), the public science and curriculum development center of the University of California, Berkeley, and the Microscopy Society of America (MSA). Microscopic Exploration supports the MSA's low-cost national outreach program and, also, reaches a very large educational community as part of the GEMS series. Some of the lessons learned through the extremely successful MSA/LHS collaboration are summarized here in hopes that they may be instructive to other scientists and educators as they launch their own partnerships and collaborations.

Fault Tolerant Control of Magnetic Bearings

2001 ◽  
Author(s):  
Uhn Joo Na ◽  
Andrew Provenza ◽  
Alan B. Palazzolo ◽  
Benjamin Choi ◽  
Gerald Montague ◽  
...  
Keyword(s):  
Fault Tolerant ◽  
System Simulation ◽  
Magnetic Bearing ◽  
Rotating Machinery ◽  
Test Results ◽  
Magnetic Forces ◽  
Failure State ◽  
Simulation Results ◽  
Test Verification ◽  
Good Agreement

Abstract This paper provides a new algorithm and test verification for implementing fault-tolerant operation of magnetically suspended, flexible shaft, rotating machinery. The currents to the magnetic bearing are redistributed in a manner so that the bearing actuator preserves the same linearized magnetic forces after some of its coils experience failure. The algorithm that searches a database for the appropriate failure compensation matrix utilizes a Boolean description of the failure state to quickly locate and download its target. The test results are shown to have good agreement with the system simulation results presented.

Numerical Impact Simulation of Aircraft Into Reinforced Concrete Walls With Different Thickness

2018 ◽  
Author(s):  
Kazuma Hirosaka ◽  
Hidekazu Takazawa ◽  
Katsumasa Miyazaki ◽  
Norihide Tohyama ◽  
Hiroyuki Nouji ◽  
...  
Keyword(s):  
Experimental Data ◽  
Simulation Model ◽  
Impact Analysis ◽  
Impact Test ◽  
Test Results ◽  
Physical Damage ◽  
Concrete Wall ◽  
Concrete Walls ◽  
Simulation Results ◽  
The Relationship

Aircraft impact analysis is needed for a safety assessment of nuclear power plants. One of the contents which should be analysed for aircraft impact is physical damage of a concrete building and this can be estimated by a numerical simulation. In order to conduct aircraft impact analysis, simulation model which validated by some experimental data needs to be established. In 1990s, impact test using actual F4 Phantom fighter was conducted at Sandia national laboratory in U.S. and a lot of important experimental data were measured. In this paper, the numerical simulation results for this F4 Phantom impact test are introduced. The relationship between the thickness of the shell of the F4 Phantom simulation model and the deceleration of this model is indicated and the differences of the deceleration between simulation and test results are discussed. In addition, the relationship between fracture strain of the shell of the F4 Phantom simulation model and the destruction mode of this model in simulation is indicated and the differences between the destruction mode of the F4 Phantom between simulation and test results are discussed. In order to evaluate the physical damage area after the aircraft impact, it is necessary to estimate the aircraft velocity after it perforates the outer concrete wall and to calculate the decrease of the kinematic energy of the aircraft by this perforation. In this paper, several aircraft impact simulations with different concrete wall thickness are conducted and the reduction in kinematic energies of an aircraft by a perforation is estimated. Using these simulation results, the necessary numbers of concrete walls until the impacting aircraft stops is discussed.

Preliminary Results for the Experimental Evaluation of a Radwaste Repository Near-Field Model

1993 ◽  
Vol 333 ◽  
Author(s):  
C. H. Kang ◽  
J. O. Lee ◽  
P. S. Hahn ◽  
H. H. Park
Keyword(s):  
Radioactive Waste ◽  
Experimental Evaluation ◽  
Field Model ◽  
Near Field ◽  
University Of California ◽  
Series Of Experiments ◽  
Waste Repository ◽  
Basic Ideas ◽  
The University ◽  
Good Agreement

ABSTRACTA series of experiments for a simplified system has been performed to evaluate a near-field model of radioactive waste repository developed by the University of California, Berkeley. In the experiments, iodine as nonsorbing species and cesium as sorbing species were employed. This paper presents the initial 200-day results of these experiments. Good agreement is found between the model and the experimental results. The results of this work will give basic ideas on the design of the near field of a repository.

Research into seismic retrofit of reinforced concrete bridge columns

1992 ◽  
Vol 25 (3) ◽  
pp. 203-210
Author(s):  
M. J. Nigel Priestley ◽  
Frieder Seible
Keyword(s):  
Reinforced Concrete ◽  
Concrete Columns ◽  
University Of California ◽  
Concrete Bridge ◽  
Test Results ◽  
Relevant Research ◽  
Reinforced Concrete Bridge ◽  
Extensive Test ◽  
Ductility Capacity ◽  
The University

Structural deficiencies in flexural and shear strength, and in ductility capacity of reinforced concrete columns of Californian bridges have required the development of effective and economic retrofit solutions. The paper describes relevant research at the University of California San Diego, and presents design recommendations based on rather extensive test results.

Test and Theory Correlation Study for a Flexible Rotor on Fault-Tolerant Magnetic Bearings

2002 ◽  
Vol 124 (3) ◽  
pp. 359-366 ◽  
Author(s):  
Uhn Joo Na ◽  
Alan B. Palazzolo ◽  
Andrew Provenza
Keyword(s):  
Fault Tolerant ◽  
Correlation Study ◽  
Magnetic Bearing ◽  
Test Results ◽  
Flexible Rotor ◽  
Magnetic Forces ◽  
Failure State ◽  
Simulation Results ◽  
Test Verification ◽  
Good Agreement

This paper provides a new algorithm and test verification for implementing fault-tolerant operation of magnetically suspended, flexible shaft, rotating machinery. The currents to the magnetic bearing are redistributed in a manner so that the bearing actuator preserves the same linearized magnetic forces after some of its coils experience failure. The algorithm that searches a database for the appropriate failure compensation matrix utilizes a Boolean description of the failure state to quickly locate and download its target. The test results are shown to have good agreement with the system simulation results presented.

Design of All-Dielectric Ultra-Wideband Transparent Water-Based Absorber

2021 ◽  
Author(s):  
Yi Lu ◽  
Juan Chen ◽  
Jianxing Li
Keyword(s):  
Thermal Stability ◽  
Energy Harvesting ◽  
Frequency Band ◽  
Oblique Incidence ◽  
Ultra Wideband ◽  
Test Results ◽  
Good Thermal Stability ◽  
Water Based ◽  
Simulation Results ◽  
Good Agreement

Abstract In this paper, an all-dielectric water-based transparent absorber is proposed. It is composed of transparent resin material filled with water, thus achieving the characteristics of all-dielectric and transparency. The simulation results show that the proposed absorber can achieve the absorptivity of more than 90% in the frequency band of 7.28-28.22GHz, and has good thermal stability and oblique incidence angular stability. The thickness of the absorber is only 6.5mm, corresponding to 0.16λmax~0.61λmin. The test results are in good agreement with the simulation results, which proves that the water-based absorber has good performance. It can be applied in the field of electromagnetic(EM) stealth, EM energy harvesting and EM shielding.

scholarly journals Safe reopening of college campuses during COVID-19: The University of California experience in Fall 2020

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0258738
Author(s):  
Brad H. Pollock ◽  
A. Marm Kilpatrick ◽  
David P. Eisenman ◽  
Kristie L. Elton ◽  
George W. Rutherford ◽  
...  
Keyword(s):  
Public Health ◽  
Health And Safety ◽  
College Campuses ◽  
Health Science ◽  
University Of California ◽  
Test Results ◽  
California Department ◽  
School Year ◽  
Public Health Data ◽  
The University

Background Epidemics of COVID-19 in student populations at universities were a key concern for the 2020–2021 school year. The University of California (UC) System developed a set of recommendations to reduce campus infection rates. SARS-CoV-2 test results are summarized for the ten UC campuses during the Fall 2020 term. Methods UC mitigation efforts included protocols for the arrival of students living on-campus students, non-pharmaceutical interventions, daily symptom monitoring, symptomatic testing, asymptomatic surveillance testing, isolation and quarantine protocols, student ambassador programs for health education, campus health and safety pledges, and lowered density of on-campus student housing. We used data from UC campuses, the UC Health–California Department of Public Health Data Modeling Consortium, and the U.S. Census to estimate the proportion of each campus’ student populations that tested positive for SARS-CoV-2 and compared it to the fraction individuals aged 20–29 years who tested positive in their respective counties. Results SARS-CoV-2 cases in campus populations were generally low in September and October 2020, but increased in November and especially December, and were highest in early to mid-January 2021, mirroring case trajectories in their respective counties. Many students were infected during the Thanksgiving and winter holiday recesses and were detected as cases upon returning to campus. The proportion of students who tested positive for SARS-CoV-2 during Fall 2020 ranged from 1.2% to 5.2% for students living on campus and was similar to students living off campus. For most UC campuses the proportion of students testing positive was lower than that for the 20–29-year-old population in which campuses were located. Conclusions The layered mitigation approach used on UC campuses, informed by public health science and augmented perhaps by a more compliant population, likely minimized campus transmission and outbreaks and limited transmission to surrounding communities. University policies that include these mitigation efforts in Fall 2020 along with SARS-CoV-2 vaccination, may alleviate some local concerns about college students returning to communities and facilitate resumption of normal campus operations and in-person instruction.

scholarly journals Intercomparison of High-Precision ∆14C Analyses Using Gas Counting and AMS

Radiocarbon ◽  
1995 ◽  
Vol 37 (2) ◽  
pp. 791-795 ◽  
Author(s):  
Ellen R. M. Druffel ◽  
Douglas J. Donahue ◽  
Sheila Griffin ◽  
George S. Burr
Keyword(s):  
High Precision ◽  
High Intensity ◽  
Ion Source ◽  
University Of California ◽  
Precision Measurements ◽  
The Third ◽  
University Of Arizona ◽  
The University ◽  
Good Agreement

We report results of a three-year intercomparison experiment between the WHOI Radiocarbon Laboratory (now at University of California, Irvine) and the NSF-University of Arizona AMS Laboratory. The purpose of this study was to compare high-precision measurements of samples obtained routinely using gas proportional counting techniques with results obtained using AMS techniques. Three sets of annually banded, modern coral samples were used for the intercomparison. Each sample was acidified to CO2 at WHOI and split into two fractions. The larger fraction was converted to acetylene gas and counted at WHOI in quartz, gas-proportional beta counters. The smaller fractions were converted to graphite and analyzed for 14C using AMS techniques at the University of Arizona. Results of the three sample sets are presented. Except for a single outlier, the data from the two laboratories are in good agreement. Of the 13 samples in the third set of the intercomparison, for which a new high-intensity ion source was in operation at the Arizona AMS laboratory, agreement of results is excellent. This finding indicates that measurements made with precisions of < 3% are reproducible at both laboratories.

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