Material-Oriented Regularization Toward Solving Manufacturing Inverse Problem in Ion Beam Microprocessing

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Q. Zhang ◽  
X. P. Zhu ◽  
B. Zhu ◽  
M. K. Lei ◽  
D. M. Guo
Keyword(s):  
Inverse Problem ◽  
Elastic Strain ◽  
Ion Beam ◽  
Elastic Strain Energy ◽  
Forward Problem ◽  
Problem Solution ◽  
Processing Load ◽  
Residual Surface Stress ◽  
Surface Stresses ◽  
Material Constraints

Abstract A material-oriented regularization (MOR) methodology is developed to solve manufacturing inverse problem of estimating the manufacture input process parameters for a required output performance, demonstrated by ion beam microprocessing of tungsten components in future fusion reactors. The MOR methodology is explored as following steps: forward problem modeling, identification of characteristic material loading, and solving the inverse problem via the characteristic material loading. A thermodynamic model is established in forward problem scheme by comprehensively incorporating material constraints of tungsten, to simulate the output of residual surface stresses in top layer of several μm that determines fatigue performance of the microprocessed tungsten component. With the experimentally verified model, all material loading variables, i.e., thermal, elastic strain, and plastic strain energies can be explicitly described under the processing load of thermal energy input. Among the material loading variables, stored elastic strain energy is identified as characteristic material loading with a highest sensitivity in correlation to residual surface stresses, as process signature. The processing load of 2.1–4.2 J/cm2 is derived for a required residual surface stress in range of 0–1500 MPa within 15 μm depth, with an upper bound of the relative error of 4.7–11.7% for the inverse problem solution. The MOR enables comprehensive incorporation of material constraints with a self-convergence effect to effectively relax the ill-posedness of manufacturing inverse problems, otherwise in conventional regularizations such constraints have to be empirically adjusted in compromise with data fitting.

scholarly journals Persamaan Lorenz untuk Keamanan Nomor Serial Sistem Operasi Window7

2019 ◽  
Vol 10 (2) ◽  
pp. 1
Author(s):  
Dewanto Harwin Rohan ◽  
Nur Hayati
Keyword(s):  
Inverse Problem ◽  
Forward Problem ◽  
Security Level ◽  
Problem Solution ◽  
Kutta Method ◽  
Lorenz Equations ◽  
Lorenz Equation ◽  
Inverse Problem Solution ◽  
Runge Kutta Method ◽  
Runge Kutta

Serial number of operating system windows 7 needs to be safeguarded, so can’t be used by the others. Security of the data can use by modern cryptography such as Vernam Cipher methods and classic cryptography such as Caesar Cipher methods. The security level both of this method depends on the keywords used and it will difficult to crack if the random key is used more and more. To get a random key, we can take from chaos of Lorenz equations as key-generator for encryption and description. Before utilizing chaos in the Lorenz equations, we have to find the maximum t (time) for the inverse problem solution to fit with the forward problem solution. We can use Runge-Kutta method in the Lorenz equations for forward problem solution and inverse problem solution. The solution of integral that obtained by the Runge-Kutta method can be searched by Trapezoidal method. The result of Runge-Kutta solution and Trapezoidal will be used as key-generator for encryption and description. In the simulations performed, the best orde in Runge-Kutta method is 4 and t max is 2. The encryption key is used as the initial condition of Lorenz equation, then the result is integrable by the Trapezoidal method. The result of orde 4 from Runge-Kutta method and Trapezoidal method used as a key-generator.  Application of Lorenz equation as key-generator for encryption and decryption, may change the cryptography algorithms of symmetric to be asymmetric.

Framework for Flaw Detection: Application to Dynamic Crack Detection in Flat Membranes

2008 ◽  
Author(s):  
Daniel Rabinovich ◽  
Dan Givoli ◽  
Shmuel Vigdergauz
Keyword(s):  
Inverse Problem ◽  
Crack Detection ◽  
Flexible Structures ◽  
Flaw Detection ◽  
Forward Problem ◽  
Dynamic Crack ◽  
Computational Framework ◽  
Time Harmonic ◽  
Present Context ◽  
Flat Membranes

A computational framework is developed for the detection of flaws in flexible structures. The framework is based on posing the detection problem as an inverse problem, which requires the solution of many forward problems. Each forward problem is associated with a known flaw; an appropriate cost functional evaluates the quality of each candidate flaw based on the solution of the corresponding forward problem. On the higher level, the inverse problem is solved by a global optimization algorithm. The performance of the computational framework is evaluated by considering the detectability of various types of flaws. In the present context detectability is defined by introducing a measure of the distance between the sought flaw and trial flaws in the space of the parameters characterizing the configuration of the flaw. The framework is applied to crack detection in flat membranes subjected to time-harmonic and transient excitations. The detectability of cracks is compared for these two cases.

Do muscles function as adaptable locomotor springs?

2002 ◽  
Vol 205 (15) ◽  
pp. 2211-2216 ◽  
Author(s):  
Stan L. Lindstedt ◽  
Trude E. Reich ◽  
Paul Keim ◽  
Paul C. LaStayo
Keyword(s):  
Skeletal Muscle ◽  
Elastic Strain ◽  
Strain Energy ◽  
Elastic Strain Energy ◽  
Normal Animal ◽  
Eccentric Contractions ◽  
Normal Muscle ◽  
Energetic Costs ◽  
Locomotor Muscles ◽  
Power Outputs

SUMMARYDuring normal animal movements, the forces produced by the locomotor muscles may be greater than, equal to or less than the forces acting on those muscles, the consequences of which significantly affect both the maximum force produced and the energy consumed by the muscles. Lengthening (eccentric)contractions result in the greatest muscle forces at the lowest relative energetic costs. Eccentric contractions play a key role in storing elastic strain energy which, when recovered in subsequent contractions, has been shown to result in enhanced force, work or power outputs. We present data that support the concept that this ability of muscle to store and recover elastic strain energy is an adaptable property of skeletal muscle. Further, we speculate that a crucial element in that muscle spring may be the protein titin. It too seems to adapt to muscle use, and its stiffness seems to be`tuned' to the frequency of normal muscle use.

The Elastostatic Axisymmetric Problem of a Cracked Sphere Embedded in a Dissimilar Matrix

1980 ◽  
Vol 47 (3) ◽  
pp. 545-550 ◽  
Author(s):  
R. Kant ◽  
D. B. Bogy
Keyword(s):  
Elastic Strain ◽  
Strain Energy ◽  
Elastic Strain Energy ◽  
Companion Paper ◽  
Infinite Medium ◽  
Applied Mechanics ◽  
Axisymmetric Solution ◽  
Material Parameters ◽  
The Difference ◽  
Elastostatic Problem

The axisymmetric elastostatic problem of a cracked sphere embedded in a dissimilar matrix is solved by using the solution for a spherical cavity in an infinite medium together with the axisymmetric solution for a cracked sphere given in the companion paper in this issue of the Journal of Applied Mechanics, Pages 538-544. Numerical results are presented for (a) interface stress for various composites (b) dependence of the stress-intensity factor on the material parameters and ratios of crack to sphere radii, (c) the difference in the elastic strain energy for a cracked and uncracked composite.

scholarly journals Effect of Joint Density on Rockburst Proneness of the Elastic-Brittle-Plastic Rock Mass

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Jiliang Pan ◽  
Fenhua Ren ◽  
Meifeng Cai
Keyword(s):  
Rock Mass ◽  
Elastic Strain ◽  
Strain Energy ◽  
Elastic Strain Energy ◽  
Jointed Rock ◽  
Jointed Rock Mass ◽  
Joint Density ◽  
Dissipated Energy ◽  
Uniaxial Compression Test ◽  
Plastic Rock

The prediction of rockburst proneness is the basis of preventing and controlling rockburst disasters in rock engineering. Based on energy theory and damage mechanics, the quantitative functional relationship between joint density and energy density was derived. Then, the theoretical results were verified by numerical simulation and uniaxial compression test, and the effect of joint density on rockburst proneness of the elastic-brittle-plastic rock mass was discussed. The results show that the relationship between the joint density and the dissipated energy index of the jointed rock mass is a logarithmic function. With the same total input energy, the higher the joint density, the more the damage dissipation energy. Even in the case of high joint density, the rock mass still has limited resistance to external failure. Under the same joint density, the strength of parallel jointed rock mass is better than that of the cross-jointed rock mass, and the parallel jointed rock mass can accumulate more elastic strain energy and has higher rockburst proneness. The joint density is closely related to the ability of the rock mass to store high strain energy. The higher the joint density is, the weaker the ability to accumulate the elastic strain energy of rock mass is and the lower the rockburst proneness is. It is helpful to predict rockburst proneness by investigating and studying the properties of geological discontinuities. The research results have some theoretical and engineering guiding significance for the prediction of rockburst proneness of the jointed rock mass.

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