Hyperelastic Constitutive Modeling of Hexagonal Honeycombs Subjected to In-Plane Shear Loading

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
Jaehyung Ju ◽  
Joshua D. Summers
Keyword(s):  
Cell Wall ◽  
Effective Properties ◽  
Nonlinear Behavior ◽  
Deformation Mode ◽  
Homogenization Method ◽  
Shear Loading ◽  
Plane Shear ◽  
Shear Property ◽  
Structural Applications ◽  
Wall Deformation

The in-plane flexible shear property of hexagonal honeycombs may be useful for the compliant structural applications. In this paper, hyperelastic strain energy functions are developed for a finite in-plane shear deformation of hexagonal honeycombs over a constituent material’s elastic range. Effective shear stress-strain curves of hexagonal structures and local cell wall deformation are investigated using the finite element based homogenization method. The hyperelastic models, which are only related to the effective properties of a honeycomb, may not be good enough to capture the nonlinear behavior at a high macroscopic shear strain level. The primary microscopic cell wall deformation mode under macroscopic in-plane shear loading was identified to be the bending of the vertical cell wall h, which is perpendicular to the macroscopic loading direction. The re-entrant hexagonal structures having a negative Poisson’s ratio shows a high macroscopic shear flexible property associated with the high h when the honeycombs are designed to have the same macroscopic shear modulus.

Experimental Damage Characterization of Hexagonal Honeycombs Subjected to In-Plane Shear Loading

2010 ◽  
Author(s):  
Shraddha Joshi ◽  
Jaehyung Ju ◽  
Luke Berglind ◽  
Roy Rusly ◽  
Joshua D. Summers ◽  
...  
Keyword(s):  
Cell Wall ◽  
Wall Thickness ◽  
Failure Modes ◽  
Shear Loading ◽  
Cell Wall Thickness ◽  
Plane Shear ◽  
Post Buckling ◽  
Proper Design ◽  
Local Cell

Experimental study on the damage of hexagonal honeycombs under in–plane shear loading does not appear to be available in the literature. In this paper, shear damage behaviors of five different hexagonal mesostructures are investigated with rapid prototyped polycarbonate (PC) honeycomb coupon samples and proper design of a fixture for shear loading. Effective shear stress-strain curves of PC honeycomb coupons are generated for each shear test and the corresponding local cell wall failure is investigated. Two different failure modes of PC honeycombs were observed primarily depending on the cell wall thickness: The PC honeycombs having a lower cell wall thickness induce the plastic post buckling, resulting in preventing propagation of initial cracks through the cell wall end up with higher plastic load bearing. On the other hand, the failure mode of the honeycombs having a high cell wall thickness is the cell wall fracture by crack propagation through wall without severe buckling.

scholarly journals An Experimental Study on Mechanical Behavior of Parallel Joint Specimens under Compression Shear

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Fei Wang ◽  
Ping Cao ◽  
Yu Chen ◽  
Qing-peng Gao ◽  
Zhu Wang
Keyword(s):  
Shear Stress ◽  
Shear Strength ◽  
Failure Mode ◽  
Shear Failure ◽  
Strain Curve ◽  
Shear Loading ◽  
Plane Shear ◽  
Joint Spacing ◽  
Dip Angle ◽  
Joint Inclination

In order to investigate the influence of the joint on the failure mode, peak shear strength, and shear stress-strain curve of rock mass, the compression shear test loading on the parallel jointed specimens was carried out, and the acoustic emission system was used to monitor the loading process. The joint spacing and joint overlap were varied to alter the relative positions of parallel joints in geometry. Under compression-shear loading, the failure mode of the joint specimen can be classified into four types: coplanar shear failure, shear failure along the joint plane, shear failure along the shear stress plane, and similar integrity shear failure. The joint dip angle has a decisive effect on the failure mode of the specimen. The joint overlap affects the crack development of the specimen but does not change the failure mode of the specimen. The joint spacing can change the failure mode of the specimen. The shear strength of the specimen firstly increases and then decreases with the increase of the dip angle and reaches the maximum at 45°. The shear strength decreases with the increase of the joint overlap and increases with the increase of the joint spacing. The shear stress-displacement curves of different joint inclination samples have differences which mainly reflect in the postrupture stage. From monitoring results of the AE system, the variation regular of the AE count corresponds to the failure mode, and the peak value of the AE count decreases with the increase of joint overlap and increases with the increase of joint spacing.

scholarly journals Analysis of Elastic Medium with Nonconcentric Two Circular Inclusions under Out-of-Plane Shear Loading.

1998 ◽  
Vol 64 (618) ◽  
pp. 438-444 ◽  
Author(s):  
Kenichi HIRASHIMA ◽  
Shigerou NAKANE ◽  
Mutsumi MIYAGAWA ◽  
Shinji KIKUCHI
Keyword(s):  
Elastic Medium ◽  
Shear Loading ◽  
Plane Shear ◽  
Out Of Plane

scholarly journals Strain rate and thermal softening effects in shear testing of AA7075-T6 sheet

2018 ◽  
Vol 183 ◽  
pp. 02037 ◽  
Author(s):  
Taamjeed Rahmaan ◽  
Ping Zhou ◽  
Cliff Butcher ◽  
Michael J. Worswick
Keyword(s):  
Strain Rate ◽  
High Speed ◽  
Rate Sensitivity ◽  
Thermal Conditions ◽  
Shear Loading ◽  
Image Correlation ◽  
High Rate ◽  
Strain Rates ◽  
Shear Testing ◽  
Plane Shear

Shear tests were performed at strain rates ranging from quasi-static (0.01 s-1) to 500 s-1 for AA7075-T6 sheet metal alloy at room temperature. A miniature sized shear specimen was used in this work to perform high strain rate shear testing. Digital image correlation (DIC) techniques were employed to measure the strains in the experiments. At maximum in-plane shear strains greater than 20%, the AA7075-T6 alloy demonstrated a reduced work hardening rate at elevated strain rates. At lower strains, the AA7075-T6 alloy showed mild positive rate sensitivity. The strain to localization (using the Zener-Holloman criterion), measured using the DIC technique, decreased with strain rate in shear loading. The strain at complete failure, however, exhibited an increase at the highest strain rate (500 s-1). The current work also focused on characterization of the thermal conditions occurring during high rate loading in shear with in situ high speed thermal imaging. Experimental results from the highest strain rate (500 s-1) tests showed a notable increase in temperature within the specimen gauge region as a result of the conversion of plastic deformation energy into heat.

Sign in / Sign up

Export Citation Format

Share Document