Design and Simulation of an Optimized Biaxial Cruciform Specimen

DOI

10.2991/978-94-6239-764-4_12How to use a DOI?

Keywords

Biaxial testing; cruciform specimen; geometry optimization; finite element analysis; Taguchi method; composite laminates

Abstract

The ability to obtain reliable biaxial test data on composite materials is based on the development of an appropriate cruciform specimen design. The best sample should be able to evenly spread stress and strain throughout the central gauge area and avoid early failure at the arm-gauge junctions. This paper aims at overcoming this difficulty by automating the geometric optimisation task using a finite element analysis alongside the Taguchi design-of-experiments approach. The geometric parameters being studied are (i) fillet radius and (ii) spline-controlled arm-gauge transition dimensions, which are varied in a systematic way to study their effects on uniformity of the stresses under equi-biaxial loading. A quarter-symmetry finite element model was established to evaluate nine distinct geometric configurations using the Taguchi L9 orthogonal array. The configurations have been analysed in the ABAQUS software platform with continuum shell elements and the Hashin damage initiation criteria. The following five measures of suitability were evaluated in the 20 x 20mm gauge area: Coefficients of variation (CV) of in-plane stress S₁₁ and S₂₂, coefficient of variation of biaxiality ratio S₂₂/S₁₁, coefficient of variation of surface strains, stress concentration factor at the arm-gauge interface, and location of failure against the gauge boundary. Three set-ups were discarded because of failure initiation that was confirmed to be beyond the gauge boundary. The best geometry attained a stress-uniformity CV of 8.4 percent, a biaxiality-ratio CV of 7.9 percent, and an SCF of 1.50, with all the damage being localized to the gauge region. These findings indicate that the use of spline-controlled transition profiles together with a sufficiently large fillet radius would yield a significantly smoother biaxial stress state compared to a sudden transition or entirely circular transition. The geometry and assessment framework suggested, therefore give a reproducible standard in the design of cruciform specimens in the characterisation of laminated composites.

Copyright

© 2026 The Author(s)

Open Access

Open Access This chapter is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/), which permits any noncommercial use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

Download article (PDF)

TY  - CONF
AU  - Abdul Mateen Mohammed
AU  - B. Deepak
PY  - 2026
DA  - 2026/09/04
TI  - Design and Simulation of an Optimized Biaxial Cruciform Specimen
BT  - Proceedings of the International Conference on Mechanics, Materials and Mechatronics (ICM³ 2026)
PB  - Atlantis Press
SP  - 141
EP  - 156
SN  - 2589-4943
UR  - https://doi.org/10.2991/978-94-6239-764-4_12
DO  - 10.2991/978-94-6239-764-4_12
ID  - Mohammed2026
ER  -