Journal ArticleDOI
Design of a Portable Compliant Device for Estimating the Failure-Load of Mesoscale Cemented Sand Specimens
TLDR
In this paper, a hand-operated compliant mechanism for estimating the failure load of cm-sized stiff objects whose stiffness is of the order of 10 s of kN/m was presented.Abstract:
In this paper, we present the design and development of a portable, hand-operated composite compliant mechanism for estimating the failure-load of cm-sized stiff objects whose stiffness is of the order of 10 s of kN/m. The motivation for the design comes from the need to estimate the failure-load of mesoscale cemented sand specimens in situ, which is not possible with traditional devices used for large specimens or very small specimens. The composite compliant device, developed in this work, consists of two compliant mechanisms: a force-amplifying compliant mechanism (FaCM) to amplify sufficiently the force exerted by hand in order to break the specimen and a displacement-amplifying compliant mechanism (DaCM) to enable measurement of the force using a proximity sensor. The two mechanisms are designed using the selection-maps technique to amplify the force up to 100N by about a factor of 3 and measure the force with a resolution of 15 mN. The composite device, made using a FaCM, a DaCM, and a Hall effect-based proximity sensor, was tested on mesoscale cemented sand specimens that were 10mm in diameter and 20mm in length. The results are compared with those of a large commercial instrument. Through the experiments, it was observed that the failure-load of the cemented sand specimens varied from 0.95N to 24.33 N, depending on the percentage of cementation and curing period. The estimation of the failure-load using the compliant device was found to be within 1.7% of the measurements obtained using the commercial instrument and thus validating the design. The details of the design, prototyping, specimen preparation, testing, and the results comprise the paper.read more
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Journal ArticleDOI
A Comparative Study of the Formulations and Benchmark Problems for the Topology Optimization of Compliant Mechanisms
TL;DR: A comparative study of five distinctly different formulations of topology optimization for the synthesis of compliant mechanisms using the same input and output specifications and the same numerical optimization algorithm.
Journal ArticleDOI
Lamina Emergent Mechanisms and Their Basic Elements
TL;DR: In this paper, the authors define lamina emergent mechanisms (LEMs) and propose a fundamental framework on which to base future LEM design, including the fundamental components (created by influencing geometry, material properties, and boundary conditions).
Journal ArticleDOI
Topology optimization for synthesis of contact-aided compliant mechanisms using regularized contact modeling
TL;DR: In this paper, a topology optimization technique for systematically designing contact-aided compliant mechanisms (CCM) is presented, which uses a smooth approximation of the unilateral displacement constraints that are used to model contact interactions.
Journal ArticleDOI
Elastoplastic model for cemented soils
A. Vatsala,A. Vatsala,Roberto Nova,Roberto Nova,B. R. Srinivasa Murthy,B. R. Srinivasa Murthy +5 more
TL;DR: In this paper, a model for bonded or cemented soils within the framework of hardening plasticity is presented based on the concepts that the strength of a cemented soil can be considered to be made up of two components, the usual strength of the soil skeleton and strength of cementation bonds, whereas the cement bonds offer additional resistance at any given strain level.
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A Building Block Approach to the Conceptual Synthesis of Compliant Mechanisms Utilizing Compliance and Stiffness Ellipsoids
TL;DR: In this paper, the authors investigate a methodology for the conceptual synthesis of compliant mechanisms based on a building block approach, which is intuitive and provides key insight into how individual building blocks contribute to the overall function.