An inverse procedure for identification of loads applied to a fractured component using a mehfree method

2020 ◽  
Author(s):  
F. Liaghat ◽  
A. Khosravifard ◽  
M. R. Hematiyan ◽  
T. Rabczuk
Keyword(s):  
Inverse Procedure

Feature Extraction of Faulty Rolling Element Bearing Based on Time Synchronous Average and Cepstrum Edit

2014 ◽  
Vol 889-890 ◽  
pp. 666-670
Author(s):  
Zong Tao Li ◽  
Yan Gao ◽  
Xiang Zhou ◽  
Yu Guo
Keyword(s):  
Feature Extraction ◽  
Phase Spectrum ◽  
Rolling Element Bearing ◽  
The Real ◽  
Discrete Frequency ◽  
Rolling Element ◽  
Frequency Components ◽  
Element Bearing ◽  
Inverse Procedure

The cepstrum edit scheme for the vibration feature extraction of the faulty rolling element bearing (REB) is studied in this paper. By combined the time synchronous average (TSA) and the real cepstrum to localize and edit the cepstral lines of the original vibration, the unwanted discrete frequency components can be removed. Then, a corresponding inverse procedure is designed, in which the edited cepstrum and the original phase spectrum are employed to reconstruct the edited vibration for the REB feature extraction. Simulation verified the scheme positively.

scholarly journals Inverse procedure for mechanical characterization of multi-layered non-rigid composite parts with applications to the assembly process

2019 ◽  
Vol 233 (17) ◽  
pp. 6167-6176
Author(s):  
Ngoc-Hung Vu ◽  
Xuan-Tan Pham ◽  
Vincent François ◽  
Jean-Christophe Cuillière
Keyword(s):  
Composite Plates ◽  
Material Model ◽  
Bending Test ◽  
Thermoplastic Composites ◽  
Assembly Process ◽  
Fiber Reinforced ◽  
Loading Test ◽  
Error Functions ◽  
Mechanical Responses ◽  
Inverse Procedure

In assembly process, non-rigid parts in free-state may have different forms compared to the designed model caused by gravity load and residual stresses. For non-rigid parts made by multi-layered fiber-reinforced thermoplastic composites, this process becomes much more complex due to the nonlinear behavior of the material. This paper presented an inverse procedure for characterizing large anisotropic deformation behavior of four-layered, carbon fiber-reinforced polyphenylene sulphide, non-rigid composite parts. Mechanical responses were measured from the standard three points bending test and the surface displacements of composite plates under flexural loading test. An orthotropic hyperelastic material model was implemented as a UMAT user routine in the Abaqus/Standard to analyze the behavior of flexible fiber-reinforced thermoplastic composites. Error functions were defined by subtracting the experimental data from the numerical mechanical responses. Minimizing the error functions helps to identify the material parameters. These optimal parameters were validated for the case of an eight-layered composite material.

Procedure to Estimate Thermophysical and Geometrical Parameters of Embedded Cancerous Lesions Using Thermography

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Jose Manuel Luna ◽  
Ricardo Romero-Mendez ◽  
Abel Hernandez-Guerrero ◽  
Francisco Elizalde-Blancas
Keyword(s):  
Research Work ◽  
Blood Perfusion ◽  
Skin Surface ◽  
Geometrical Parameters ◽  
Estimation Of Parameters ◽  
Perfusion Rate ◽  
Unknown Parameters ◽  
Cancerous Lesions ◽  
The Relationship ◽  
Inverse Procedure

Based on the fact that malignant cancerous lesions (neoplasms) develop high metabolism and use more blood supply than normal tissue, infrared thermography (IR) has become a reliable clinical technique used to indicate noninvasively the presence of cancerous diseases, e.g., skin and breast cancer. However, to diagnose cancerous diseases by IR, the technique requires procedures that explore the relationship between the neoplasm characteristics (size, blood perfusion rate and heat generated) and the resulting temperature distribution on the skin surface. In this research work the dual reciprocity boundary element method (DRBEM) has been coupled with the simulated annealing technique (SA) in a new inverse procedure, which coupled to the IR technique, is capable of estimating simultaneously geometrical and thermophysical parameters of the neoplasm. The method is of an evolutionary type, requiring random initial values for the unknown parameters and no calculations of sensitivities or search directions. In addition, the DRBEM does not require any re-meshing at each proposed solution to solve the bioheat model. The inverse procedure has been tested considering input data for simulated neoplasms of different sizes and positions in relation to the skin surface. The successful estimation of unknown neoplasm parameters validates the idea of using the SA technique and the DRBEM in the estimation of parameters. Other estimation techniques, based on genetic algorithms or sensitivity coefficients, have not been capable of obtaining a solution because the skin surface temperature difference is very small.

scholarly journals Inverse Approach to Evaluate the Tubular Material Parameters Using the Bulging Test

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Yulong Ge ◽  
Xiaoxing Li ◽  
Lihui Lang
Keyword(s):  
Finite Element ◽  
Constitutive Model ◽  
Material Properties ◽  
Hybrid Algorithm ◽  
Material Parameters ◽  
Inverse Approach ◽  
Material Evaluation ◽  
Levenberg Marquardt ◽  
Bulging Test ◽  
Inverse Procedure

Tubular material parameters are required for both part manufactory process planning and finite element simulations. The bulging test is one of the most credible ways to detect the property parameters for tubular material. The inverse approach provides more effective access to the accurate material evaluation than with direct identifications. In this paper, a newly designed set of bulging test tools is introduced. An inverse procedure is adopted to determine the tubular material properties in Krupkowski-Swift constitutive model of material deformation using a hybrid algorithm that combines the differential evolution and Levenberg-Marquardt algorithms. The constitutive model’s parameters obtained from the conventional and inverse methods are compared, and this comparison shows that the inverse approach is able to offer more information with higher reliability and can simplify the test equipment.

Computational Transonic Inverse Procedure for Wing Design

AIAA Journal ◽  
1982 ◽  
Vol 20 (8) ◽  
pp. 1044-1050 ◽  
Author(s):  
Vijaya Shankar ◽  
Norman D. Malmuth ◽  
J. D. Cole
Keyword(s):  
Wing Design ◽  
Inverse Procedure

An Inverse Procedure for Determining the Material Constants of Isotropic Square Plates by Impulse Excitation of Vibration

2006 ◽  
Vol 3-4 ◽  
pp. 287-292 ◽  
Author(s):  
Marco Alfano ◽  
Leonardo Pagnotta
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Carbon Steel ◽  
Elastic Constants ◽  
Natural Vibration ◽  
Finite Element Code ◽  
Resonant Frequencies ◽  
Material Constants ◽  
Impulse Excitation ◽  
Inverse Procedure

The paper presents a procedure whereby the Poisson’s ratio and dynamic Young’s modulus of isotropic and homogeneous materials are determined using two of the first four frequencies of natural vibration in thin square plates. The procedure is based on suitable approximate relationships relating the resonant frequencies to the elastic constants of the material. These relations were derived from an extensive series of numerical analysis carried out by a finite element code. To measure the fundamental resonant frequencies, inexpensive computerized equipment is proposed. The procedure has been validated on Carbon Steel specimens.

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