FE simulation of repaired timber beams under tensile load using CFRP patches

Timber is a highly orthotropic material with highest strength presented in tension along the grain direction. Repaired timber structural elements in pure tension using carbon fibre–epoxy patches provide new opportunities as it is well adapted to the nature of wood. Such repairing process is very interesting as it is easy to use for assembling two damaged parts of timber and has a low environmental impact. Before this process can become widespread in the industry, it is necessary to develop numerical tools for predicting the behaviour of such assemblies under tensile loads. Only a few experimental tests have been offered in the literature, and even fewer numerical studies have been carried out to analyse the complex mechanical behaviour of timber. The present paper describes the use of carbon fibre–epoxy patches for repairing timber beams under tensile stress along the grain direction. The repaired beams with CFRP patches using varying repair lengths were examined. The load-carrying capacity increased by about 47%, passing from a repair length of 5 mm (F = 3.8 kN) to a repair length of 10 mm (F = 6.6 kN) at a displacement u = 0.3 mm. A three-dimensional (3-D) numerical methodology for virtual loading process under pure tension, including the interaction between two adherent surfaces and taking the presence of an adhesive layer into account, is presented from both theoretical and numerical point of views. Predicted and measured load–displacement responses and failure modes are compared. The predicted results are in good agreement with the experimentally measured test data.     

Theoretical investigation of electronic performance,half-metallicity,and magnetic properties of Cr-substituted BaTe

We have investigated the structural, electronic, and ferromagnetic properties of chromium (Cr)-doped rocksalt BaTe (\(\hbox {Ba}_{1-x}\hbox {Cr}_{x}\hbox {Te}\)) compounds with compositions \(x = 0.25\), 0.5, and 0.75, based on density functional theory with generalized gradient approximation of Wu–Cohen (GGA-WC) and Tran–Blaha-modified Becke–Johnson (TB-mBJ) potential using the WIEN2k package. We found that the electronic structure showed half-metallic ferromagnetic character with spin polarization of 100 % around the Fermi level. In addition, the minority-spin bands depicted a half-metallic ferromagnetic (HMF) gap and half-metallic (HM) gap. The improved HMF and HM gaps found with the TB-mBJ potential are higher than with the GGA-WC approximation. These large HM gaps make \(\hbox {Ba}_{1-x} \hbox {Cr}_{x}\hbox {Te}\) compounds promising candidates for use in spintronics applications.     

Experimental and Theoretical Studies of Taxus Baccata Alkaloid Extract as Eco-Friendly Anticorrosion for Carbon Steel in Acidic Solution

Protection of Metals and Physical Chemistry of Surfaces - The effect of the alkaloid extract of Taxus baccata (AETB) as a green inhibitor of carbon steel in 1M HCl solution, were assessed. It was...