The Experts below are selected from a list of 1779 Experts worldwide ranked by ideXlab platform

Mats Werme - One of the best experts on this subject based on the ideXlab platform.

Jean B. Nganou - One of the best experts on this subject based on the ideXlab platform.

  • Stone MV-algebras and strongly complete MV-algebras
    Algebra universalis, 2017
    Co-Authors: Jean B. Nganou
    Abstract:

    Characterizations of compact Hausdorff topological MV-algebras, Stone MV-algebras, and MV-algebras that are isomorphic to their profinite completions are established. It is proved that compact Hausdorff topological MV-algebras are products (both topological and algebraic) of copies [0, 1] with the interval Topology and finite Łukasiewicz chains with the Discrete Topology. Going one step further, we also prove that Stone MV-algebras are products (both topological and algebraic) of finite Łukasiewicz chains with the Discrete Topology. Finally, it is proved that an MV-algebra is isomorphic to its profinite completion if and only if it is profinite and each of its maximal ideals of finite rank is principal.

  • Stone MV-algebras and Strongly complete MV-algebras
    arXiv: Logic, 2015
    Co-Authors: Jean B. Nganou
    Abstract:

    Compact Hausdorff topological MV-algebras and Stone MV-algebras are completely characterized. We obtain that compact Hausdorff topological MV-algebras are product (both topological and algebraic) of copies $[0,1]$ with standard Topology and finite Lukasiewicz chains with Discrete Topology. Going one step further we also prove that Stone MV-algebras are product (both topological and algebraic) of finite Lukasiewicz chains with Discrete Topology. We also prove that an MV-algebra is strongly complete (isomorphic to its profinite completion) if and only if it is profinite and its maximal ideals of finite ranks are principal.

Krister Svanberg - One of the best experts on this subject based on the ideXlab platform.

Qing Li - One of the best experts on this subject based on the ideXlab platform.

  • Simultaneous Discrete Topology Optimization of Ply Orientation and Thickness for Carbon Fiber Reinforced Plastic-Laminated Structures
    Journal of Mechanical Design, 2019
    Co-Authors: Chi Wu, Jianguang Fang, Erik Lund, Qing Li
    Abstract:

    This study developed a Discrete Topology optimization procedure for the simultaneous design of ply orientation and thickness for carbon fiber reinforced plastic (CFRP)-laminated structures. A gradient-based Discrete material and thickness optimization (DMTO) algorithm was developed by using casting-based explicit parameterization to suppress the intermediate void across the thickness of the laminate. A benchmark problem was first studied to compare the DMTO approach with the sequential three-phase design method using the free size, ply thickness, and stacking sequence of the laminates. Following this, the DMTO approach was applied to a practical design problem featuring a CFRP-laminated engine hood by minimizing overall compliance subject to volume-related and functional constraints under multiple load cases. To verify the optimized design, a prototype of the CFRP engine hood was created for experimental tests. The results showed that the simultaneous Discrete Topology optimization of ply orientation and thickness was an effective approach for the design of CFRP-laminated structures.

  • Discrete Topology optimization of ply orientation for a carbon fiber reinforced plastic cfrp laminate vehicle door
    Materials & Design, 2017
    Co-Authors: Chi Wu, Jianguang Fang, Erik Lund, Qing Li
    Abstract:

    Abstract This study addresses the design of ply orientation for a CFRP vehicle door by implementing a Discrete Material Optimization (DMO) method in a general-purpose commercial finite element code (ABAQUS) and mathematical analysis tool (MATLAB). To accommodate multiple loading conditions, the weighted mean compliance of the CFRP vehicle door was taken as the objective function, subject to the constraints on the local displacements, primary natural frequency and manufacturability. The sensitivities of objective and constraints were calculated by using the strain vectors, which is a more general method than using element stiffness matrices and allows extracting local displacements from the commercial finite element code. A gradient-based algorithm was employed in the DMO approach to tackle the large-scale problem. In the Discrete Topology optimization, four material penalization schemes were attempted in this study. The proposed DMO approach was compared with the empirical design and the existing method in commercial software. The results demonstrated that the proposed method is able to produce a more competent solution than the empirical design and other optimization methods efficiently.

Hong Zhou - One of the best experts on this subject based on the ideXlab platform.

  • Discrete Topology Optimization of Structures Without Uncertainty
    Volume 4A: Dynamics Vibration and Control, 2013
    Co-Authors: Hong Zhou, Surya Tej Kolavennu
    Abstract:

    The Topology of a structure is defined by its genus or number of handles. When the Topology of a structure is optimized, its Topology might be changed if the material state of a design cell is switched from solid to void or vice versa. In Discrete Topology optimization, each design cell is either solid or void and there is no Topology uncertainty from any grey design cell. Point connection might cause Topology uncertainty and is eradicated when hybrid discretization model is used for Discrete Topology optimization. However, the Topology solution of an optimized structure might be uncertain when its design domain is discretized differently, which is commonly called mesh dependence problem. In this paper, the degree of genus based Topology optimization strategy is introduced to circumvent this Topology uncertainty. With this strategy, the genus of an optimized structure is constrained during its Topology optimization process. There is no Topology uncertainty even if different design domain discretizations are used. The introduced strategy is used for Discrete Topology optimization of structures that have multiple loading points in this paper. The presented Discrete Topology optimization procedure is demonstrated by examples with different degrees of genus and loading conditions.Copyright © 2013 by ASME

  • Corner Elimination in Discrete Topology Optimization of Compliant Mechanisms
    Volume 4A: Dynamics Vibration and Control, 2013
    Co-Authors: Hong Zhou, Venkat S. Jangam
    Abstract:

    In Discrete Topology optimization, material state is either solid or void and there is no Topology uncertainty caused by intermediate material state. A common problem of the current Discrete Topology optimization is that boundaries are unsmooth. Unsmooth boundaries are caused by the corners in Topology solutions. Although outer corner cutting and inner corner filling strategy can mitigate corners, it cannot eliminate them. 90-degree corners are usually mitigated to 135-degree corners under the corner handling strategy. The existence of corners in Topology solutions is because of the subdivision model. If regular triangles are used to subdivide a design domain, corners are inevitable in Topology solutions. To eradicate corner from any Topology solution, an innovative subdivision model is introduced in this paper for Discrete Topology optimization of compliant mechanisms. A design domain is discretized into quadrilateral design cells and every quadrilateral design cell is further subdivided into special triangular analysis cells that have a curved hypotenuse. With the presented subdivision model, all boundaries are smooth in any Topology solution. Two Discrete Topology optimization examples of compliant mechanisms are solved based on the proposed subdivision approach.Copyright © 2013 by ASME

  • The Boundary Smoothing in Discrete Topology Optimization of Structures
    Volume 3A: 39th Design Automation Conference, 2013
    Co-Authors: Hong Zhou, Shabaz Ahmed Mohammed
    Abstract:

    In Discrete Topology optimization, material state is either solid or void and there is no Topology uncertainty caused by intermediate material state. A common problem of the current Discrete Topology optimization is that boundaries are unsmooth. Unsmooth boundaries are caused by corners in Topology solutions. Although the outer corner cutting and inner corner filling strategy can mitigate corners, it cannot eliminate them. 90-degree corners are usually mitigated to 135-degree corners under the corner handling strategy. The existence of corners in Topology solutions is because of the subdivision model. If regular triangles are used to subdivide design domains, corners are inevitable in Topology solutions. To eradicate corner from any Topology solution, a subdivision model is introduced in this paper for the Discrete Topology optimization of structures. The design domain is discretized into quadrilateral design cells and every quadrilateral design cell is further subdivided into triangular analysis cells that have a curved hypotenuse. With the presented subdivision model, all boundaries and connections are smooth in any Topology solution. The proposed subdivision approach is demonstrated by two Discrete Topology optimization examples of structures.Copyright © 2013 by ASME

  • The Uncertainty Elimination in Discrete Topology Optimization of Compliant Mechanisms
    Volume 6A: 37th Mechanisms and Robotics Conference, 2013
    Co-Authors: Hong Zhou, Satya Raviteja Kandala
    Abstract:

    Topology uncertainty leads to different Topology solutions and makes Topology optimization ambiguous. Point connection and grey cell might cause Topology uncertainty. They are both eradicated when hybrid discretization model is used for Discrete Topology optimization. A common Topology uncertainty in the current Discrete Topology optimization stems from mesh dependence. The Topology solution of an optimized compliant mechanism might be uncertain when its design domain is discretized differently. To eliminate Topology uncertainty from mesh dependence, the genus based Topology optimization strategy is introduced in this paper. The Topology of a compliant mechanism is defined by its genus which is the number of holes in the compliant mechanism. With this strategy, the genus of an optimized compliant mechanism is actively controlled during its Topology optimization process. There is no Topology uncertainty when this strategy is incorporated into Discrete Topology optimization. The introduced Topology optimization strategy is demonstrated by examples with different degrees of genus.Copyright © 2013 by ASME

  • The Discrete Topology Optimization of Structures Using the Improved Hybrid Discretization Model
    Journal of Mechanical Design, 2012
    Co-Authors: Hong Zhou, Rutesh B. Patil
    Abstract:

    In the Discrete Topology optimization, material state is either solid or void and there is no Topology uncertainty caused by any intermediate material state. In this paper, the improved hybrid discretization model is introduced for the Discrete Topology optimization of structures. The design domain is discretized into quadrilateral design cells and each quadrilateral design cell is further subdivided into triangular analysis cells. The dangling and redundant solid design cells are completely eliminated from Topology solutions in the improved hybrid discretization model to avoid sharp protrusions. The local stress constraint is directly imposed on each triangular analysis cell to make the designed structure safe. The binary bit-array genetic algorithm is used to search for the optimal Topology to circumvent the geometrical bias against the vertical design cells. The presented Discrete Topology optimization procedure is illustrated by two Topology optimization examples of structures.