We consider the deformation of a thin elastic sheet which is stiff in traction but very soft in compression, as happens in presence of wrinkling. We use the tension-field material model and explore numerically the response of a thin sheet containing multiple cracks of different geometries, when subjected to applied tension. With a single crack, the stress concentrates along a St-Andrew's cross-shaped pattern, whose branches extend from the crack tips to the corners of the domain; at a (small) distance r from the crack tip, the stress displays the usual r −1/2 stress singularity but with an unusual and non-universal angular dependence. A strong interaction between multiple cracks is reported and discussed: in particular, for certain configurations of the cracks, the tensile stiffness of a cracked sheet can be zero even though the sheet is made up of a single component.

In this research, it has been investigated the effect of addition High performance polymer Polytetrafluroethylene (PTFE) on the Ultra-high molecular weight polyethylene (UHMWPE) mechanical and physical properties. It has been prepared three types of blends (95:5, 90:10 and 85:15)

Different types of long and short multiwalled carbon nanotubes (MWCNTs) were used as structural support in epoxy resin with a percentage of weight (0.1,0.2,0.5,1.0,1.5,2.0,2.5,3.0,3.5,4.0,4.5,&5) wt. percent, Utilization of direct mixing processes to prepare Nano-Composites (Epoxy/MWCNTs). The ultrasonic mixing method has been used to disperse the nanotubes into the epoxy resin system. SEM was used to demonstrate the dispersion in the epoxy polymer matrix of different MWCNT concentrations. The findings show that electrical conductivity properties boost effect, thermal conductivity coefficient, and A.C with percentage enhancement of less than 2 percent, and then raising with further raise in the content of MWCNTs.

In this study the magnetic nanoparticles of Co1-XZnXFe2O4 were prepared with different X values (X = 0, 0.1, 0.3, 0.5, 0.7 and 0.9 respectively), using co-precipitation method. The ferrites with a Nano scale was ranging from (10 to28 nm), and the structural properties were tasted prepared samples using X-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM). The structural results showed that the particles have a cubic spindle phase and that the particles have a Nano scale, with a clear agglomeration between the particles sites Finally, the magnetic properties tests showed that the particles have high magnetic saturation.