کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8129822 1523179 2018 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Determination of elastic moduli from measured acoustic velocities
ترجمه فارسی عنوان
تعیین مدول الاستیک از سرعت آکوستیک اندازه گیری شده
کلمات کلیدی
ثابتهای انعطاف پذیر، ماژول انعطاف پذیر، امواج صوتی، امواج سطحی، امواج بدن، سونوگرافی، بریلوین، پراکندگی نور تحریک شده تحریک کننده، برآورد پارامتر حداقل مربعات غیر خطی،
موضوعات مرتبط
مهندسی و علوم پایه فیزیک و نجوم آکوستیک و فرا صوت
چکیده انگلیسی
Methods are evaluated in solution of the inverse problem associated with determination of elastic moduli for crystals of arbitrary symmetry from elastic wave velocities measured in many crystallographic directions. A package of MATLAB functions provides a robust and flexible environment for analysis of ultrasonic, Brillouin, or Impulsive Stimulated Light Scattering datasets. Three inverse algorithms are considered: the gradient-based methods of Levenberg-Marquardt and Backus-Gilbert, and a non-gradient-based (Nelder-Mead) simplex approach. Several data types are considered: body wave velocities alone, surface wave velocities plus a side constraint on X-ray-diffraction-based axes compressibilities, or joint body and surface wave velocities. The numerical algorithms are validated through comparisons with prior published results and through analysis of synthetic datasets. Although all approaches succeed in finding low-misfit solutions, the Levenberg-Marquardt method consistently demonstrates effectiveness and computational efficiency. However, linearized gradient-based methods, when applied to a strongly non-linear problem, may not adequately converge to the global minimum. The simplex method, while slower, is less susceptible to being trapped in local misfit minima. A “multi-start” strategy (initiate searches from more than one initial guess) provides better assurance that global minima have been located. Numerical estimates of parameter uncertainties based on Monte Carlo simulations are compared to formal uncertainties based on covariance calculations.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ultrasonics - Volume 90, November 2018, Pages 23-31
نویسندگان
,