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Acceptance criteria for validation metrics in roadside safety based on repeated full-scale crash tests

International Journal of Reliability and Safety 2010年第1期4卷 69-88页

作者： Mongiardini, Mario Ray, Malcolm H. Anghileri, Marco Department of Civil and Environmental Engineering Worcester Polytechnic Institute 100 Institute Road Worcester MA 01609 United States Department of Aerospace Engineering Politecnico di Milano via La Masa 34 Milan 20156 Italy 'LAST' impact laboratory United Kingdom WPI's Impact Engineering Program United Kingdom Structural Mechanics Impact Laboratory United States

This paper proposes acceptance criteria for quantitative comparison metrics to be applied in the Verification and Validation (V&V) process of computational models used in roadside safety. Typically, the degree of verification or validation of a numerical model is assessed by qualitatively comparing the shapes of two curves, but qualitative comparisons are subjective and open to interpretation. Using quantitative comparison metrics in the V&V process allows for an objective measure of the reliability of a numerical model. Two comparison metrics were selected from a group of 16 metrics found in the literature. Acceptance criteria suitable to the typical scatter of full-scale crash tests were established by comparing ten essentially identical vehicle redirectional crash tests. Since the tests were as identical as can be achieved experimentally, the values of the quantitative metrics represented the reasonable range for the metric corresponding to matched experiments. Typical residual errors expected in full-scale tests are also discussed. Copyright © 2010 Inderscience Enterprises Ltd.

关键词： Numerical models

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Fatigue crack propagation property of friction stir welded 2024-T3 aluminum alloy

Fatigue crack propagation property of friction stir welded 2...

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作者： Kuwayama, Kazuya Asakawa, Motoo Okada, Takao Nakamura, Toshiya Machida, Shigeru Fujita, Shinya Dept.of Engineering of Mechanics Graduate School Waseda University Tokyo 169-8555 Japan Dept.of Engineering of Mechanics Waseda University Tokyo 169-8555 Japan Aviation Program Group Japan Aerospace Exploration Agency Tokyo 181-0015 Japan Dept.of Engineering of Mechanics Undergraduate School Waseda University Tokyo 169-8555 Japan

ISBN: (纸本)9781563479731

Fatigue crack propagation tests on friction stir welded aluminum alloy sheets were carried out to investigate the effect of residual stress on the crack propagation rate. In these tests, the effect of the inclination angle of the weld line on the direction of crack propagation was also investigated. The test results show that crack propagation rate is accelerated by high tensile residual stress around the weld line. The angle of the weld line does not affect the crack propagation rate and direction. This behavior of crack propagation cannot be explained by the consideration of residual stress value alone. The estimation of effective stress range from the crack opening stress is required to satisfactorily evaluate the crack propagation rate of friction stir welded specimens. Copyright © 2009 by the American Institute of Aeronautics and Astronautics, Inc.

关键词： Residual stresses

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Comparison of load path definitions in 2-D continuum structures

Comparison of load path definitions in 2-D continuum structu...

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作者： Marhadi, Kun S. Venkataraman., Satchi Computational Science Program San Diego State University San Diego CA 92182-1308 United States Department of Aerospace Engineering and Engineering Mechanics San Diego State University Mail Code 1308 5500 Campanile Drive San Diego CA 92182-1308 United States

ISBN: (纸本)9781563479731

The structural mechanics community has developed several methods to identify and visualize load paths in structures. There is no single accepted approach or method to characterize, quantify, visualize and tailor load paths. This paper compares various methods proposed to characterize and visualize load paths. The comparison is performed for a two-dimensional (2-D) rectangular plate under plane stress conditions arising from different loading and boundary conditions. The effectiveness and computational effort of each method are compared. The comparisons shows the methods provide different results and insights into the load transfer mechanisms. No single method appears to emerge as a clear choice for characterizing load paths. However, some methods provide more qualitative and quantitative information on the trajectory and efficiency of load transfer along load paths. Copyright © 2009 by the authors.

关键词： Rectangular plate

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Annual business and news:: Beginning the 31st year of the Journal of Guidance, Control, and Dynamics

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2008年第1期31卷 1-1页

作者： Schmidt, George T. Aeronautics and Astronautics Massachusetts Institute of Technology (MIT) AIAA Institute of Electrical and Electronics Engineers Russian Federation Academy of Navigation and Motion Control Department of Mechanical and Aerospace Engineering and Engineering Mechanics University of Missouri-Rolla(UMR) Lockheed Electronics Company Center for Space Research University of Texas Austin United States Wright Laboratory Eglin Air Force Base UMR AIAA Guidance Navigation and Control Technical Committee American Automatic Control Council Lockheed Martin Aeronautics Company Palmdale CA United States C4ISR and Unmanned Air Vehicle (UAV) Programs for Air Vehicle Sciences and Systems Accreditation Board Engineering and Technology Inc./Aeronautical National Technical Committee on Guidance Navigation and Control Department of Mechanical and Aerospace Engineering University at Buffalo State University of New York (SUNY) AIAA Technical Committee on GN and C Air Vehicles Directorate Air Force Research Laboratory (AFRL) Wright-Patterson Air Force Base Space Access and Hypersonic Vehicle Guidance and Control Group Control Science Center of Excellence AFRL AIAA Technical Committee on Guidance Navigation and Control Department of Mechanical and Aeronautical Engineering University of California (UC) Davis United States Boeing Company Modernized Flight Control System for the Apache Longbow AIAA Institute of Electrical and Electronics Engineers AHS Jet Propulsion Laboratory California Institute of Technology Boeing Company Flight Sciences and Advanced Design Group Guidance Navigation and Control (GN and C) Systems Engineer Distributed Space Systems NASA Goddard Space Flight Center (GSFC) AIAA GN and C Technical Committee Department of Aerospace Engineering and Engineering Mechanics University of Texas Austin United States Institute of Navigation American Astronautical Society AIAA Guidance Navigation (GN and C) and Control Technical Committee Department of Aerospace Engineering Iowa State University Iowa

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Study on the intravenous lung assist device (ILAD) using PZT actuators and PVDF sensors

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Key engineering Materials 2008年 381-382卷 353-356页

作者： Kim, G.B. Kim, S.J. Lee, Y.C. Hong, C.U. Kang, H.S. Kim, J.S. Kim, S.Z. Yoon, S.J. Kim, M.H. Education Program for 21st Century Chonbuk National University Research Institute of Clinical Medicine Duckjin-Dong Jeonju Jeonbuk 561-756 Korea Republic of Department of Bio and Applied Chemistry Iksan National Collage Ma-Dong Iksan Jeonbuk 570-752 Korea Republic of Department of Internal Chonbuk National University Medical Schools Duckjin-Dong Jeonju Jeonbuk 561-752 Korea Republic of Division of Bionics and Bioinformatics Collage of Engineering Chonbuk National University Duckjin-Dong Jeonju Jeonbuk 561-756 Korea Republic of Department of Pharmacology Collage of Veterinary Medicine Chonbuk National University Duckjin-Dong Jeonju Jeonbuk 561-756 Korea Republic of Department of Physiology Center for Healthcare Technology Development Chonbuk National University Medical Schools Duckjin-Dong Jeonju Jeonbuk 561-756 Korea Republic of Division of Mechanics and Aerospace Engineering Collage of Engineering Chonbuk National University Duckjin-Dong Jeonju Jeonbuk Korea Republic of Department of Thoracic and Cardiovascular Surgery Chonbuk National University Medical Schools Duckjin-Dong Jeonju Jeonbuk 561-756 Korea Republic of

The purpose of this study was to investigate the effect of vibration device in gas transfer rate for usage as intravenous lung assist device. Specific attention was focused on the effect of membrane vibration. Quantitative experimental measurements were performed to evaluate the performance of the device, and to identify membrane vibration dependence on hemolysis. Scaling analysis was then used to infer the dimensionless groups that correlate the performance of a vibrated hollow tube membrane oxygenator. The experimental design and procedure are then given for a device for assessing the effectiveness of membrane vibrations. This ILAD is used to provide some insight into how wall vibrations might enhance the performance of an intravascular lung assist device. The time and the frequency response of PVDF sensor were investigated through various frequencies in the ILAD. In these devices, the flow of blood and the source of oxygen were separated by a semipermeable membrane allows oxygen to diffuse into and out of the fluid, respectively. The results of experiments have shown vibrating ILAD performs effectively.

关键词： Oxygen

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Prediction of austenite-martensite interfaces in CuAlNi around a notch tip

Prediction of austenite-martensite interfaces in CuAlNi arou...

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SEM Annual Conference and Exposition on Experimental and Applied mechanics 2006

作者： Creuziger, A. Shield, T.W. Crone, W.C. Engineering Mechanics Program University of Wisconsin - Madison 1500 Engineering Drive Madison WI 53706 Department of Aerospace Engineering and Mechanics University of Minnesota 110 Union St. SE Minneapolis MN 55455 Department of Engineering Physics University of Wisconsin - Madison 1500 Engineering Drive Madison WI 53706

ISBN: (纸本)091205395X

Experiments and predictions of the location and type of martensitic deformations for arbitrarily oriented crystals of CuAlNi are presented in this research. It has been shown that an available work criterion can be used to successfully predict these deformations at a notch tip in samples that obey a plane stress or plane strain condition, for which there is an analytic solution for the stress field. In this work, finite element analysis (FEA) is used to determine the stress field for non-planar crystallographic orientations that are investigated experimentally. Applying the available work criterion, comparisons between the calculated martensite deformations and experimental tests were found to be reasonably accurate.

关键词： Copper compounds

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Incorporating model uncertainties and variability in optimization of laminates for predictable failure

Incorporating model uncertainties and variability in optimiz...

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11th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference

作者： Salas, Pablo Venkataraman, Satchi San Diego State University San Diego CA 92182 Joint Doctoral Program in Engineering Sciences and Applied Mechanics San Diego State University University of California San Diego AIAA Department of Aerospace Engineering and Engineering Mechanics San Diego State University Mail Code 1308 5500 Campanile Drive San Diego CA 92182

ISBN: (纸本)1563478234

Safety and reliability of engineering systems are affected by uncertainties from four sources: (i) inherent variability in the physical variables, (ii) modeling errors, (iii) estimation errors and (iv) human errors. In this paper, we investigate the second source, namely the effect of modeling uncertainties on the predictability and robustness of progressive failure response in composites. Modeling uncertainties exist in the homogenization models used for stiffness calculations, in micromechanics models used for calculating the ply or constituent level stresses, in the phenomenological and mechanistic failure criteria used for predicting failure, and in the models used to degrade ply properties after initial failure. This paper investigates the effects of different modeling uncertainties on the predictability and robustness of progressive failure response for different composite laminate designs. The interaction of model uncertainties with physical variability is also investigated. It is shown that reliability optimization for variability provides designs that have robust energy absorption when analyzed with model uncertainties but do not have a predictable failure sequence. To achieve a predictable failure sequence requires including model uncertainties along with variability in the reliability optimization.

关键词： Laminates

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Hybrid sensor network for large array sensing systems for acoustic source localization in solid media

Hybrid sensor network for large array sensing systems for ac...

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47th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference

作者： Ghosha, Anindya Kim, Heung Soo Chattopadhyay, Aditi Applied Mechanics Group United Technologies Research Center East Hartford CT 06108 Department of Mechanical Engineering Inha University Incheon Korea Republic of Department of Mechanical and Aerospace Engineering Arizona University Tempe AZ 85287-6106 Sikorsky Program PHM UTRC AIAA

ISBN: (纸本)1563478080

This is a concept paper developing the hybrid sensor network concept using a combinatorial approach of physical and virtual/model sensor arrays for acoustic source localization in solid media. This paper outlines the hybrid sensor network concept, virtual sensing system, and the associated sensor architecture. It elaborates on the physical sensor review, sensor characterization and evaluation process for damage and load sensors and the corresponding vendors. The model sensor grid concept is developed using predictive reduced order models for baseline and then updated using feedback loops from load and damage physical sensors. Some of the ongoing research on sensor placement strategies including binary sensing has been illustrated. The sensor placement strategies involve a combinatorial approach involving physical damage and load sensors to be strategically placed on a virtual sensor grid network. Copyright © 2006 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

关键词： Sensor networks

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Effect of competing failures and load redistributions on progressive failure predictability in truss structures

Effect of competing failures and load redistributions on pro...

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11th AIAA/ISSMO Multidisciplinary Analysis and Optimaztion Conference

作者： Marhadi, Kun Venkataraman, Satchi San Diego State University San Diego CA 92182-1308 United States Computational Science Program AIAA United States Department of Aerospace Engineering and Engineering Mechanics San Diego State University Mail Code 1308 5500 Campanile Drive San Diego CA 92182-1308 United States

ISBN: (纸本)1563478234

The progressive failure of redundant truss structures was investigated. Energy absorption of the truss under progressive failure is taken as a measure of its performance. The non-deterministic energy absorption when small random design variations were introduced was calculated. Measures for robustness and predictability are proposed. Designs with different performance, robustness and predictability identified using a deterministic optimization procedure are investigated and characteristics that contribute to better energy absorption, robustness and predictable progressive failure are identified. The presence of competing failures is shown to lead to competing failure sequences. Investigating the failure sequence events and the energy absorption of competing failure sequences in non-robust designs indicate that energy absorption is a function of the stiffness of the competing member that fails first. To improve the total energy dissipated, failure sequences must be tailored so that the stiffer members whose failures do not lead to the structure becoming mechanism fails before the less loaded and less stiff members that are needed to keep the structure intact fail. To improve predictability, competing failures must be eliminated by separating the safety factors of critical members at each failure event.

关键词： Trusses

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Processing and characterization of epoxy/SWCNT/woven fabric composites

Processing and characterization of epoxy/SWCNT/woven fabric ...

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47th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference

作者： Thakre, Piyush R. Lagoudas, Dimitris C. Zhu, Jiang Barrera, Enrique V. Gates, Thomas S. Materials Science and Engineering Program Department of Aerospace Engineering Texas A and M University College Station TX 77840 United States NanoRidge Materials Inc. Houston TX 77023 United States Department of Mechanical Engineering and Materials Science Rice University Houston TX 77005 United States NASA Langley Research Center Mechanics of Structures and Materials Branch Hampton VA 23681 United States Aerospace Engineering 3141/TAMU United States AIAA United States NanoRidge Materials Inc. 2315 Schlumberger St. Houston TX 77023 United States Mechanical Engineering and Materials Science 1892/RICE United States Mechanics of Structures and Materials Branch MS188E United States

ISBN: (纸本)1563478080

The objective of the proposed paper is to present a processing technique, test methods, experimental results, and manufacturing concerns related to mechanical performance of composite laminates with selective reinforcement using single walled carbon nanotubes (SWCNTs). Vacuum assisted resin transfer molding (VARTM) was used to fabricate woven carbon fabric-epoxy matrix composite laminates with localized placement of SWCNTs. The interlaminar shear strength of 8 harness satin weave carbon-epoxy composite was studied using short beam shear test and microscopy. The composites were manufactured with the nanotubes placed in the laminate mid-plane. Both pristine (non-functionalized) and functionalized SWCNTs were used in the mid-plane and compared to laminates without any nanotubes. The interlaminar shear strength was found to be improved by using functionalized nanotubes with little or almost no improvement for the case of the pristine nanotubes. Microscopic investigation of crack initiation and propagation is presented using results from optical and scanning electron microscopy. Copyright © 2006 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

关键词： Epoxy resins

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