Design of a Portable Compliant Device for Estimating the Failure-Load of Mesoscale Cemented Sand Specimens

Bhargav, Santosh DB and Kandasami, Ramesh K and Murthy, Tejas G and Ananthasuresh, GK (2015) Design of a Portable Compliant Device for Estimating the Failure-Load of Mesoscale Cemented Sand Specimens. In: JOURNAL OF MECHANICAL DESIGN, 137 (6).

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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.

Item Type:	Journal Article
Publication:	JOURNAL OF MECHANICAL DESIGN
Publisher:	ASME
Additional Information:	Copy right for this article belongs to the ASME, TWO PARK AVE, NEW YORK, NY 10016-5990 USA
Keywords:	composite compliant mechanism; cemented sand specimen; spring-lever model; selection-maps
Department/Centre:	Division of Mechanical Sciences > Civil Engineering Division of Mechanical Sciences > Mechanical Engineering
Date Deposited:	15 Jun 2015 05:09
Last Modified:	15 Jun 2015 05:09
URI:	http://eprints.iisc.ac.in/id/eprint/51634

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