The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
Luis Norberto Lopez De La Calle - One of the best experts on this subject based on the ideXlab platform.
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methodology for the design of a Thermal Distortion compensation for large machine tools based in state space representation with kalman filter
International Journal of Machine Tools & Manufacture, 2013Co-Authors: Eneko Gomezacedo, Aitor Olarra, Javier Orive, Luis Norberto Lopez De La CalleAbstract:Abstract A methodology for the design of a Thermal Distortion compensation system is presented which will assist the manufacturing processes to reach higher levels of accuracy when working with large machines in common shop floor environments. A parametric state-space representation was selected as model architecture, providing multiple inputs and outputs capability and a compact formulation that takes into account previous Thermal states of the machine. Inputs for the model are spindle speed and temperatures of main motor gearbox and room air. Outputs are the estimations of the Thermal drift of the machine tool centre point along the three axes in different positions within the working volume. Model parameters were numerically identified with initial experimental tests performed in a large gantry-type milling machine, measuring mentioned variables and also Thermal Distortion values using a reference artifact along with non-contact proximity sensors. Proposed model was finally verified with a new validation measurement in the machine. Obtained results revealed 80% of error reduction in the vertical axis which comprised 70% of total Thermal effects and 50% in the longitudinal X axis which comprised 25% of total Thermal effects. Also it was concluded that the model benefits from using valuable information about the machine state from previous spindle speed register instead of using only temperature values. Proposed methodology benefits from providing a feasible implementation in real shop floor conditions without the necessity of including additional temperature sensors or probing systems in the machine.
Guanping Wang - One of the best experts on this subject based on the ideXlab platform.
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Analysis on dynamics of a cutting tool with the Thermal Distortion in turning process
Nonlinear Dynamics, 2016Co-Authors: An Wang, Wuyin Jin, Guanping WangAbstract:The Thermal Distortion of the cutting tool is an important factor that can affect machining precision. A new single degree of freedom chatter model of the regenerative orthogonal turning process takes into account the Thermal Distortion of the cutting tool is proposed in this work. The cutting tool of the turning system is modeled as one-dimensional oscillator with nonlinear stiffness and the Thermal Distortion both in axial and in radial direction. Numerical method is employed to explore the effect of the largest Thermal Distortion on the dynamics of the cutting system. The results show that the motion of the cutting tool will transition among periodic, quasi-periodic, and chaotic motions with the time delay and the largest Thermal Distortion changed, at the same time, the different bifurcation patterns are found that indicate the dynamics of the cutting system is influenced by the largest Thermal Distortion. In addition, the stability of cutting system will be broken earlier with the increase in the largest Thermal Distortion.
Pei Gu - One of the best experts on this subject based on the ideXlab platform.
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Influence of Thermal Distortion to compression failure of polymer matrix composite panels in fire
Composite Structures, 2012Co-Authors: Pei Gu, Wen ChenAbstract:Abstract This paper discusses the influence of Thermal Distortion to compression failure load of polymer matrix composite panels in fire. The Thermal gradient along the thickness of the panel, caused by low Thermal conductivity, induces transverse deformation field even without external mechanical loads, known as Thermal Distortion. The deformation field of Thermal Distortion obtained from combined Thermal–mechanical analysis is presented in terms of non-dimensional parameters that represent Thermal and mechanical properties, including those in phase transition at high temperature range, and dimensional lengths. A failure model is proposed to assess the transition from Euler buckling to plastic compression failure under the influence of Thermal Distortion. For large slenderness ratio, the panel is failed by Euler buckling. For small slenderness ratio, the panel is failed by plastic failure mechanism, where the analysis quantifies the influence of Thermal Distortion to the reduction of load-bearing capacity. The compression failure mechanism under the influence of Thermal Distortion is discussed for developing quantitative approach to design polymer matrix composite structures in fire.
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influence of material nonlinearity on Thermal Distortion of polymer matrix composite panels
Composites Part B-engineering, 2010Co-Authors: Pei Gu, Robert J AsaroAbstract:Abstract This paper discusses the influence of material nonlinearity on Thermal Distortion of polymer matrix composite panels. The load is transverse temperature gradient introduced by one-sided heat exposure, e.g., fire. For such low Thermal conductivity materials, when there are no external mechanical loads, the transverse Thermal gradient induces non-uniform Thermal expansion along the thickness that results in transverse deformation field, known as Thermal Distortion. The power form stress–strain relation and the Ramberg–Osgood form stress–strain relation are discussed to include the temperature dependent behavior of polymer matrix composites. The degradation of polymer matrix composites at elevated temperature, Thermal softening, is discussed. The variations of the reference stress and the reference strain with temperature are specified to describe the temperature dependent constitutive relationships. Semi-analytical simulation and finite element simulation are carried out for panels with roller end support condition. Results suggest that, while the material nonlinearity has insignificant influence on the transverse displacement of the panel, it has strong influence on local stress and strain. The stress and strain can go beyond the yield stress and the yield strain into plastic stage in certain circumstances.
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Distortion of polymer matrix composite panels under transverse Thermal gradients
Composite Structures, 2008Co-Authors: Pei Gu, Robert J AsaroAbstract:This paper discusses the Distortion of panels made by fiber reinforced polymer matrix composites under transverse Thermal-loading conditions. This is the continuation of our previous paper [Gu P, Asaro RJ. Structural buckling of polymer matrix composites due to reduced stiffness from fire damage. Compos Struct 2005;69:65–75] on fire performance of polymer matrix composites, in particular, the continuation of the discussion given in the last section of the paper for Thermal Distortion of the composite panels. We formulate Thermal Distortion from the bending theory of functionally graded materials. General solution for Thermal Distortion is derived in terms of material variation and temperature profile along the thickness of the panels. Using the general solution, analytical expressions of Thermal Distortion and associated internal forces for commonly used end supports are obtained. From these solutions, we discuss the failure mechanism induced by Thermal Distortion and design criteria that can be placed to prevent such failure. The roles of geometry, temperature and temperature gradients, and the competition among them in the process of structural failure are addressed.
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Distortion of polymer matrix composite panels under transverse Thermal gradients
Volume 2: Computer Applications Technology and Bolted Joints, 2007Co-Authors: Pei Gu, Robert J AsaroAbstract:This paper discusses the Distortion of panels made by fiber reinforced polymer matrix composites under transverse Thermal-loading conditions. We formulate Thermal Distortion from the bending theory of functionally graded materials. General solution for Thermal Distortion is derived in terms of material variation and temperature profile along the thickness of the panels. Using the general solution, analytical expressions of Thermal Distortion and associated internal forces for commonly used end supports are obtained. From these solutions, we discuss the failure mechanism induced by Thermal Distortion and design criteria that can be placed to prevent such failure. The roles of geometry, temperature and temperature gradients, and the competition among them in the process of structural failure are addressed.Copyright © 2007 by ASME
Robert J Asaro - One of the best experts on this subject based on the ideXlab platform.
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influence of material nonlinearity on Thermal Distortion of polymer matrix composite panels
Composites Part B-engineering, 2010Co-Authors: Pei Gu, Robert J AsaroAbstract:Abstract This paper discusses the influence of material nonlinearity on Thermal Distortion of polymer matrix composite panels. The load is transverse temperature gradient introduced by one-sided heat exposure, e.g., fire. For such low Thermal conductivity materials, when there are no external mechanical loads, the transverse Thermal gradient induces non-uniform Thermal expansion along the thickness that results in transverse deformation field, known as Thermal Distortion. The power form stress–strain relation and the Ramberg–Osgood form stress–strain relation are discussed to include the temperature dependent behavior of polymer matrix composites. The degradation of polymer matrix composites at elevated temperature, Thermal softening, is discussed. The variations of the reference stress and the reference strain with temperature are specified to describe the temperature dependent constitutive relationships. Semi-analytical simulation and finite element simulation are carried out for panels with roller end support condition. Results suggest that, while the material nonlinearity has insignificant influence on the transverse displacement of the panel, it has strong influence on local stress and strain. The stress and strain can go beyond the yield stress and the yield strain into plastic stage in certain circumstances.
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Distortion of polymer matrix composite panels under transverse Thermal gradients
Composite Structures, 2008Co-Authors: Pei Gu, Robert J AsaroAbstract:This paper discusses the Distortion of panels made by fiber reinforced polymer matrix composites under transverse Thermal-loading conditions. This is the continuation of our previous paper [Gu P, Asaro RJ. Structural buckling of polymer matrix composites due to reduced stiffness from fire damage. Compos Struct 2005;69:65–75] on fire performance of polymer matrix composites, in particular, the continuation of the discussion given in the last section of the paper for Thermal Distortion of the composite panels. We formulate Thermal Distortion from the bending theory of functionally graded materials. General solution for Thermal Distortion is derived in terms of material variation and temperature profile along the thickness of the panels. Using the general solution, analytical expressions of Thermal Distortion and associated internal forces for commonly used end supports are obtained. From these solutions, we discuss the failure mechanism induced by Thermal Distortion and design criteria that can be placed to prevent such failure. The roles of geometry, temperature and temperature gradients, and the competition among them in the process of structural failure are addressed.
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Distortion of polymer matrix composite panels under transverse Thermal gradients
Volume 2: Computer Applications Technology and Bolted Joints, 2007Co-Authors: Pei Gu, Robert J AsaroAbstract:This paper discusses the Distortion of panels made by fiber reinforced polymer matrix composites under transverse Thermal-loading conditions. We formulate Thermal Distortion from the bending theory of functionally graded materials. General solution for Thermal Distortion is derived in terms of material variation and temperature profile along the thickness of the panels. Using the general solution, analytical expressions of Thermal Distortion and associated internal forces for commonly used end supports are obtained. From these solutions, we discuss the failure mechanism induced by Thermal Distortion and design criteria that can be placed to prevent such failure. The roles of geometry, temperature and temperature gradients, and the competition among them in the process of structural failure are addressed.Copyright © 2007 by ASME
D.-h. Choi - One of the best experts on this subject based on the ideXlab platform.
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ICA based Thermal source extraction and Thermal Distortion compensation method for a machine tool
International Journal of Machine Tools and Manufacture, 2003Co-Authors: Dong Soo Lee, Jin Young Choi, D.-h. ChoiAbstract:Thermal Distortion in machine tools is one of the most significant causes of machining errors. One of the difficult issues in developing a system to compensate for Thermal Distortion is to select the appropriate temperature variables and to obtain an accurate Thermal Distortion model. This paper presents a new Thermal Distortion compensation method based on the Independent Component Analysis (ICA) method. The ICA method was used to extract the Thermal sources from the temperature variables. The Optimal Brain Surgeon (OBS) algorithm was used to reduce the temperature variables with insignificant information. Using the extracted sources, a new Thermal Distortion model and a compensation method is proposed and is implemented in real-time hardware. In these experiments, the proposed method was shown to be capable of compensating for Thermal Distortions to a few micrometers.
