Delamination Mechanics

Liechti, Kenneth M.

doi:10.1007/978-0-387-30877-7_34

Cited by 2 publications

(5 citation statements)

References 99 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, a constant Tresca contour will be a close approximation of the isochromatic fringe patterns at the point of interest. 32 Figures 21 and 22 show the Tresca equivalent stress contours for the examined gears at the pitch point and LPSTC of the pinion (HPSTC of the gear). Despite the fact that residual cutting stresses were not included in these stress contours, they exhibit a fair approximation to the photoelastic fringe patterns illustrated in Figures 8 to 12.…”

Section: Resultsmentioning

confidence: 99%

Experimental stress analysis of enhanced sliding contact spur gears using transmission photoelasticity and a numerical approach

Hussein

Abdullah

2023

Proceedings of the Institution of Mechanical Engineers, Part C:

View full text Add to dashboard Cite

Free-Form-Gear (FFG) is a recently published title for a gear that has a curved path of contact and offers contact between a convex addendum and a concave dedendum during the meshing cycle. Based on this method of designing a gear pair, the path of contact can be altered to improve the way the gears mesh and slide against each other by only adjusting the maximum pressure angle and the involute curve parameter. The analytical investigations into this gear pair indicated that, when compared to the standard involute gear pair, the sliding velocity, meshing efficiency, contact, and fillet strengths are improved while the contact ratio is decreased. In this study, experimental stress analysis is conducted on various configurations of the tooth profile and tooth fillet shape for the proposed FFG and the standard involute gear to validate the analytical results. Since it is difficult to measure the contact stress for the gear specimens, the contact stresses at critical points are estimated using an effective computational technique based on photoelastic data and a numerical approach utilizing the nonlinear least squares method. At the fillet zone, isochromatic fringe patterns are used to directly measure the maximum fillet stress. Using addendum modification coefficients, the reduction in contact ratio for the proposed FFG is eliminated, and the results are then verified experimentally. Based on the experimental estimations, the finite element analyses are conducted using ABAQUS to simulate the examined gear specimens. Under the same loading conditions, the experimental, analytical, and numerical results have all been in good agreement.

show abstract

Section: Resultsmentioning

confidence: 99%

Experimental stress analysis of enhanced sliding contact spur gears using transmission photoelasticity and a numerical approach

Hussein

Abdullah

2023

Proceedings of the Institution of Mechanical Engineers, Part C:

View full text Add to dashboard Cite

show abstract

“…Delamination could occur during fully elastic or elastoplastic deformations of a multilayer structure. Delamination during elastic deformation is mainly due to a mismatch in mechanical properties of adjacent layers which leads to a mismatch in deformations and separation of adhesive layers [86]. For example, a flexible display supported by high stiffness protective layers on both sides is likely to delaminate due to a mismatch in deformations [87].…”

Section: Delaminationmentioning

confidence: 99%

“…It involves formulation of global and local strain energy release rates. In theory, if a susceptible spot in the adhesive layer is shielded from global loading (local strain energy release rate is smaller than global strain energy release rate), its delamination failure will not occur [86].…”

Section: Delaminationmentioning

confidence: 99%

“…25, the protective films on both sides of the display have a grooved shape in the folding region. The purpose is to distribute the folding stresses to a larger area to reduce the stresses when the display is folded [86,104]. To show the effect of the grooved layers on mitigating shear stresses, we performed a finite element study on a representative geometry of a display assembly.…”

Section: Delaminationmentioning

confidence: 99%

“…Another method for Fig. 25 Reduction of shear stresses using grooves in the protective films [86,104]. A grooved structure has more freedom to deform in response to shear stresses.…”

Section: Bucklingmentioning

confidence: 99%

See 2 more Smart Citations

A Review on United States Patents to Prevent Mechanical Failures in Foldable Smartphones

Nematollahisarvestani

Lee

2020

Journal of Electronic Packaging

View full text Add to dashboard Cite

A foldable smartphone is an exciting new approach for future mobile systems. With some early models being introduced to the market, research and development is being performed to increase the reliability of future systems. Mechanical failure of the display is the major source of foldable smartphone’s reliability issues. The display is a laminate structure including an organic light emitting diode (OLED) layer (emission layer and pixel electrode layer), a touch panel, a polarizer, and multiple protective layers in addition to multiple functional coatings and supporting structures. The display is exposed to repeated folding, finger touch and the impact of external sharp objects. In addition, mechanical behavior changes through the thickness of the display; which adds extra challenges in preventing damage to vital components of the display. This review covers more than 100 US patents about the mechanical failures in foldable smartphones published or filed after 2015. Different inventions reviewed are to design a foldable configuration to prevent mechanical failures resulting from the following four mechanisms: 1) plastic deformation (yielding, creep, and fatigue); 2) fracture; 3) delamination; and 4) buckling (warping, buckling, wrinkling and creasing).

show abstract

Delamination Mechanics

Cited by 2 publications

References 99 publications

Experimental stress analysis of enhanced sliding contact spur gears using transmission photoelasticity and a numerical approach

Experimental stress analysis of enhanced sliding contact spur gears using transmission photoelasticity and a numerical approach

A Review on United States Patents to Prevent Mechanical Failures in Foldable Smartphones

Contact Info

Product

Resources

About