scholarly journals Effect of interfacial stiffness on the stretchability of metal/elastomer bilayers under in-plane biaxial tension

Author(s):  
Zheng Jia ◽  
Teng Li
Author(s):  
D. L. Rohr ◽  
S. S. Hecker

As part of a comprehensive study of microstructural and mechanical response of metals to uniaxial and biaxial deformations, the development of substructure in 1100 A1 has been studied over a range of plastic strain for two stress states.Specimens of 1100 aluminum annealed at 350 C were tested in uniaxial (UT) and balanced biaxial tension (BBT) at room temperature to different strain levels. The biaxial specimens were produced by the in-plane punch stretching technique. Areas of known strain levels were prepared for TEM by lapping followed by jet electropolishing. All specimens were examined in a JEOL 200B run at 150 and 200 kV within 24 to 36 hours after testing.The development of the substructure with deformation is shown in Fig. 1 for both stress states. Initial deformation produces dislocation tangles, which form cell walls by 10% uniaxial deformation, and start to recover to form subgrains by 25%. The results of several hundred measurements of cell/subgrain sizes by a linear intercept technique are presented in Table I.


Author(s):  
Lei Su ◽  
Qing An ◽  
Jiejie Li ◽  
Lin Wang ◽  
Yuhang Zhang ◽  
...  

Author(s):  
Nedunchezhian Srinivasan ◽  
R. Velmurugan ◽  
Lalith Kumar Bhaskar ◽  
Satish Kumar Singh ◽  
Bhanu Pant ◽  
...  

2021 ◽  
Vol 11 (12) ◽  
pp. 5720
Author(s):  
Saeid Taghizadeh ◽  
Robert Sean Dwyer-Joyce

When two rough surfaces are loaded together contact occurs at asperity peaks. An interface of solid contact regions and air gaps is formed that is less stiff than the bulk material. The stiffness of a structure thus depends on the interface conditions; this is particularly critical when high stiffness is required, for example in precision systems such as machine tool spindles. The rough surface interface can be modelled as a distributed spring. For small deformation, the spring can be assumed to be linear; whilst for large deformations the spring gets stiffer as the amount of solid contact increases. One method to measure the spring stiffness, both the linear and nonlinear aspect, is by the reflection of ultrasound. An ultrasonic wave causes a perturbation of the contact and the reflection depends on the stiffness of the interface. In most conventional applications, the ultrasonic wave is low power, deformation is small and entirely elastic, and the linear stiffness is measured. However, if a high-powered ultrasonic wave is used, this changes the geometry of the contact and induces nonlinear response. In previous studies through transmission methods were used to measure the nonlinear interfacial stiffness. This approach is inconvenient for the study of machine elements where only one side of the interface is accessible. In this study a reflection method is undertaken, and the results are compared to existing experimental work with through transmission. The variation of both linear and nonlinear interfacial stiffnesses was measured as the nominal contact pressure was increased. In both cases interfacial stiffness was expressed as nonlinear differential equations and solved to deduce the contact pressure-relative surface approach relationships. The relationships derived from linear and nonlinear measurements were similar, indicating the validity of the presented methods.


2007 ◽  
Vol 101 (3) ◽  
pp. 033540 ◽  
Author(s):  
Geoffrey H. Campbell ◽  
Gregory C. Archbold ◽  
Omar A. Hurricane ◽  
Paul L. Miller
Keyword(s):  

1995 ◽  
Vol 30 (5) ◽  
pp. 474-483
Author(s):  
P. A. Zinov'ev ◽  
S. V. Tsvetkov

2014 ◽  
Vol 658 ◽  
pp. 167-172 ◽  
Author(s):  
Liviu Andrusca ◽  
Viorel Goanta ◽  
Paul Doru Barsanescu

Testing cruciform specimens subjected to biaxial tension is one of the most widely used experimental techniques and more accurate at this time to determine the mechanical properties of materials and to verify the failure theories. This type of experiment allows the continuous monitoring of behavior of materials from the beginning of deformation until fracture under different ratios of forces and directions of the deformation, which transforms it into a very versatile testing method. We have varied the number of parameters and their values in order to achieve a uniform distribution of biaxial state of stresses and strains in the area tested. In theory, any material can be tested by stretching a biaxial cruciform specimen, but must be investigated in what way the shape of the specimen influence the data obtained. In this paper are presented the requirements that must be fulfilled by the samples used for tensile / compression biaxial tests and the design of cruciform specimens through FEA that meet these demands.


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