Let Ω ⊂ R be a bounded open set. Given 2 ≤ m ≤ n, we construct a convex function φ : Ω → R whose gradient f = ∇φ is a Hölder continuous homeomorphism, f is the identity on ∂Ω, the derivative Df has rank m − 1 a.e. in Ω and Df is in the weak L space L. The proof is based on convex integration and staircase laminates.

It is understood that nano-channels of graphene oxide membranes have a water flow mechanism which is similar to the water flow inside carbon nanotube pores. The water transport mechanisms recently proposed by various researchers suggest that membranes composed of graphene oxide laminates could be regarded as an assembly of many tiny carbon nanotubes stacked together with attached functional gro...

The growing use of marine composite materials has led to many technical challenges and one is predicting lifetime durability. This analysis step has a large uncertainty due to the lack of data from in-service composite vessels. Analytical models based on classical lamination theory, finite-element analysis, ship motions, probability and wind and wave mechanics were used in this project to predi...

A computational study is performed to determine the contribution to ultrasound attenuation in carbon fiber reinforced polymer composite laminates of linear elastic scattering by matrix micro-cracking. Multiple scattering approximations are benchmarked against exact computational approaches. Results support linear scattering as the source of observed increased attenuation in the presence of micr...

Fiber metal laminates (FMLs) have been successfully manufactured by the vacuum assisted resin transfer molding (VARTM) process developed at NASA Langley Research Center. A flow visualization fixture of the FML, VARTM process was constructed and used to observe the resin infiltration process. Results of the flow visualization experiments are reported and compared with the predictions of a VARTM ...

Interlaminar fracture toughness in carbon fiber reinforced plastics has been studied primarily using unidirectional or symmetric laminates. However, even quasi-isotropic laminates, delamination caused by an out-of-plane impact could result asymmetric, partial Thus, evaluating the interlaminar asymmetric particularly that of Mode II associated with resistance, is necessary. Asymmetric laminates ...

This study focuses on mechanical characterization of carbon fiber reinforced polymer (CFRP) laminates with non-treated and treated multiwalled nanotubes (CNTs) using nitric acid. The CNTs were acid to obtain carboxylic functional group. epoxy resins are mixed 0.3%wt at a constant mixing speed 2000 rpm times varied from 24 96 h. Laminates show an increase in the flexural strength by 17.4 15.3% h...