Minimum weight

About: Minimum weight is a research topic. Over the lifetime, 2002 publications have been published within this topic receiving 28244 citations.

Determination of optimum particle size of Al2O3/SiCp reinforced hybrid composites materials in wear testing

Abstract: Purpose – The purpose of this study is to optimize input parameters of particle size and applied load to determine minimum weight loss and friction coefficient for Al2O3/SiC particles-reinforced hybrid composites by using Taguchi’s design methodology. Design/methodology/approach – The experimental results demonstrate that the applied size is the major parameter influencing the weight loss for all samples, followed by particle size. The applied load, however, was found to have a negligible effect on the friction coefficient. Moreover, the optimal combination of the testing parameters was predicted. The predicted weight loss and friction coefficient for all the test samples were found to lie close to those of the experimentally observed ones. Findings – The optimum levels of the control factors to obtain better weight loss and friction coefficient were A8 (particle size, 60 μm) and B1 (applied load, 20 N), respectively. Taguchi’s orthogonal design was developed to predict the quality characteristics (weight...

Numerical Optimization of the Tube-Cored Induction Magnetometer Weight Under Specific Noise Constraints

Abstract: The aim of this paper is to achieve the minimum weight for the induction magnetometer (IM) with specific noise constraints. First, a tube magnetic core was used to decrease the weight and achieve a similar magnetic concentrating performance as the rod one. The parameters, including the coil resistance, the inductance, the apparent permeability with different coil-to-core length ratios, and the noise equivalent magnetic induction, were evaluated theoretically. A chopping pre-amplifier circuit was used to suppress the $1/f$ noise in low frequencies. Finally, the optimization problem proposed from the practical applications was solved using the penalty function method (interior point method). To verify the theoretical analysis, the optimal IM was manufactured and tested. The experimental results showed 3.1 pT/ $\surd $ Hz at 1 Hz, noise floor 22 fT/ $\surd $ Hz, and total weight 0.52 kg, which were well coincided with the theoretical calculation. Moreover, the relationships among the noise constraints and the coil weight were also discussed.

Local Search for Minimum Weight Dominating Set with Two-Level Configuration Checking and Frequency Based Scoring Function

Abstract: The Minimum Weight Dominating Set (MWDS) problem is an important generalization of the Minimum Dominating Set (MDS) problem with extensive applications. This paper proposes a new local search algorithm for the MWDS problem, which is based on two new ideas. The first idea is a heuristic called two-level configuration checking (CC2), which is a new variant of a recent powerful configuration checking strategy (CC) for effectively avoiding the recent search paths. The second idea is a novel scoring function based on the frequency of being uncovered of vertices. Our algorithm is called CC2FS, according to the names of the two ideas. The experimental results show that, CC2FS performs much better than some state-of-the-art algorithms in terms of solution quality on a broad range of MWDS benchmarks.

Overlap-stiffened panels for optimized buckling performance under minimum steering radius constraints

Abstract: Recent research on variable stiffness laminates have shown both numerically and experimentally that further improvement on the buckling performance is possible by incorporating overlaps that result in variable thickness profiles. We present the concept of overlap-stiffened designs that take advantage of the non-linear coupling between the tow steering and the local thickness, allowing embedded regions of higher stiffness into individual plies of a variable-angle tow (VAT) laminate. The proposed method naturally copes with minimum steering radius constraints of different manufacturing processes by connecting transition regions by means of fiber tow arcs, such that the radius of curvature always cope with a desired minimum radius constraint. The present study focuses on two tow-steering processes: automated fiber placement (AFP) and continuous tow shearing (CTS). Each individual ply exploring the overlap-stiffened design is described using 5 design variables, producing a straight stiffener. A first benchmark study compares overlap-stiffened laminates optimized for a maximum volume-normalized buckling performance under bi-axial compression against a reference straight-fiber laminate. In a second benchmark, overlap-stiffened panels were optimized for minimum weight under a design buckling load constraint, and compared against a reference straight-fiber laminate. For both AFP and CTS, is verified that overlap-stiffened VAT panels can achieve at least the double of the volume-normalized buckling performance of an optimized straight-fiber panel. Moreover, the proposed design method can at least achieve the same weight and buckling load carrying capacity of an optimal straight-fiber panel, demonstrating the potential of the proposed design method to include embedded regions of higher thickness.

Minimum-Weight Design of Machine Foundation Under Vertical Load

Abstract: In this paper a numerical model for the minimum‐weight design of a rectangular machine foundation under a harmonic vertical load is presented The analysis of the dynamics of foundation‐soil interaction is based on frequency‐dependent dynamic properties of a semi‐infinite supporting medium and includes the shape of the foundation plan, the embedment of the foundation into the soil, and hysteretic material damping of the soil Dimensions of the concrete block are assumed as design variables Constraints are placed on resonant frequency, vertical displacement amplitude, stresses in the soil and dimensions of the foundation concrete block A sequential programming method with variable move limits is used to obtain the optimal solution, which is affected by inertia properties of the machine‐foundation‐soil system, damping from dynamic soil‐foundation interaction and local soil conditions Numerical examples are given to demonstrate the applications of the proposed approach