Torsion apparatus for measuring shear properties of adhesive bonded joints

Bossler, F C; Franzblau, M C; Rutherford, J.L.

doi:10.1088/0022-3735/1/8/318

Cited by 13 publications

(5 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several testing methods have been developed to assess the properties of materials, including single-lap shear tests Adams, 1989;Pinto et al, 2009) and peel tests (Kaelble, 1992;Thouless and Jensen, 1992). An alternative approach involves the use of a napkin-ring specimen (Bossler et al, 1968;Liechti and Hayashi, 1989;Chai, 1993Chai, , 2004 along with a modified tensile/torque test method to mitigate stress concentration effects (Richardson et al, 2003;Mahnken and Schlimmer, 2005;Spaggiari et al, 2013;Teutenberg et al, 2013). However, this technique requires an accurate biaxial testing apparatus, which is only available to a limited number of research institutions.…”

Section: Evaluation Of Plastic Formability Of Layered Metal Sheets Bo...mentioning

confidence: 99%

Evaluation of plastic formability of layered metal sheets bonded by adhesives using conical cup testing

XUE,

SHIBUTANI

2024

Mechanical Engineering Journal

View full text Add to dashboard Cite

Adhesive bonding is the preferred method for joining dissimilar materials owing to the low weight of adhesives. To evaluate the application of adhesive bonding to multi-materialization, in this study, we used conical cup testing as an integrated formability test method to assess the forming limit of bonded multi-layered metal sheets, comparing them with the equivalent unitary sheets. The conical cup testing equipment used in this study was designed and produced based on JIS Z 2249, with a viewing port that can be used to observe the deformed bottom of the specimens during the conical cup test. Multi-layered specimens composed of aluminum (Al) and steel (steel plate cold-rolled commercial (SPCC) steel) layers were produced using acrylic and epoxy adhesives, and single-(material)-layered specimens composed of layers of the same material were also produced. In addition, the unitary specimens of the materials without any bonding were examined as reference materials. The experimental results showed that the forming limits of the single-(material)-layered Al specimens (pure aluminum A1050 and aluminum alloy A5052) were nearly identical to those of the unitary specimens. Therefore, the use of the adhesive improved the formability of the Al sheet to that of the corresponding unitary specimen with twice the thickness. The results of the A5052-SPCC multi-layered specimen bonded by acrylic adhesive were compared with those of the SPCC unitary specimen, and its forming limit increased by 35% with a notable 33% reduction in weight, demonstrating the enhanced performance of the multi-layer structure. The reason for the improvement in formability may be the suppression of the abrupt increase in surface roughness, which otherwise leads to plastic instability.

show abstract

Section: Evaluation Of Plastic Formability Of Layered Metal Sheets Bo...mentioning

confidence: 99%

Evaluation of plastic formability of layered metal sheets bonded by adhesives using conical cup testing

XUE,

SHIBUTANI

2024

Mechanical Engineering Journal

View full text Add to dashboard Cite

show abstract

“…As a result, these measurements are not appropriate to fit the failure criterion. To avoid the stress concentration effect, a shear stress test using a napkin-ring specimen has been proposed [20][21][22][23] and used in a tension-torque test method [24,25] so that the failure criterion in multiaxial stress state can be estimated by experimental results. It is a good way to evaluate the failure criterion without a free-edge effect, but this method requires a highly accurate biaxial testing machine which may be difficult to access for most institutions generally.…”

Section: Failure Criterion Of Adhesivementioning

confidence: 99%

Shape optimization of adhesives of multi-materials under multiaxial stress failure criteria

Yang

Tanaka

Shibutani

2022

The Journal of Adhesion

View full text Add to dashboard Cite

In recent years, multi-material design concept has been applied to many industries. Among various methods of joining dissimilar materials, adhesive bonding is quite suitable for the purpose of lightening the weight. In order to choose the most preferable adhesive for improvement of the strength, it is necessary to understand the failure criteria of adhesives. Experiments using pipe specimens with inclined surfaces bonded by an epoxy adhesive were performed, which can achieve multiaxial stress states while solely recurring to a uniaxial tensile test. The failure function of the epoxy adhesive, expressed by the mean stress and octahedral shear stress, was then obtained from the experiment data and compared with that of the acrylic adhesive in the previous research. The failure functions of both adhesives were then applied to the shape optimization of the adhesive layer under different loading conditions. The optimization object is to improve the strength of bonded structures. The optimal shape for different loading conditions differs for each adhesive because of the driving force due to the applied stress. Thus, the final shapes are numerically optimized to attain the highest mechanical integrity of the adhesive layer and show strong dependences on the initial shapes prior to optimization.

show abstract

“…A few tests do avoid initiation at a sharp ''corner'' and generate relatively smooth stress distributions. The shear napkin-ring test [10] is one such example. For a test geometry with an outer radius of 9.25 mm and an inner radius of 8.25 mm, the shear stresses vary by only 2% within the sample), and the local surface traction is approximated well by the macroscopic torque divided by the mean radius and sample area.…”

Section: Historical Testsmentioning

confidence: 99%

Critical Tractions for Initiating Adhesion Failure at Interfaces in Encapsulated Components

Adolf

Chambers

Stavig

et al. 2006

The Journal of Adhesion

View full text Add to dashboard Cite

Determining the initiation of adhesive failure at a surface buried deep within the bulk of an epoxy is qualitatively different from measuring the propagation of an existing surface crack. Most current tests are shown to be unsuitable for assessing the critical traction at initiation. A new test geometry is presented that initiates failure away from an air interface, produces a slowly varying stress distribution near the initiation site and minimal contributions from thermal residual stresses, and enables tests with mixed modes of loading. This new geometry is used to examine temperature-dependent adhesive failure in tensile, shear, and mixed modes of loading for both smooth and rough surfaces. Some of the experimental results are unexpected. As examples, the critical traction at initiation of adhesive failure is apparently insensitive to surface roughness, and the critical normal traction is independent of temperature while the critical tangential traction tracks the shear yield stress.

show abstract

Torsion apparatus for measuring shear properties of adhesive bonded joints

Cited by 13 publications

References 3 publications

Evaluation of plastic formability of layered metal sheets bonded by adhesives using conical cup testing

Evaluation of plastic formability of layered metal sheets bonded by adhesives using conical cup testing

Shape optimization of adhesives of multi-materials under multiaxial stress failure criteria

Critical Tractions for Initiating Adhesion Failure at Interfaces in Encapsulated Components

Contact Info

Product

Resources

About