Micro-crack

This study proposes a constitutive mechanical law to model the behavior of the interface between a microcracked viscoelastic medium and an undamaged elastic body based on the homogenization method. The interface is modeled by a layer of zero thickness. The coupling between the homogenization technique and the Griffith’s theory is used to provide the effective behavior of the micro-cracked medium.

15p vithomson 02-07-2024 2 0   Download

In this study, masonry infills are considered a building envelope with loadbearing function. A finite element procedure for the effective properties of microcracked viscoelastic masonry based on homogenization technique is provided to take into account the influence of crack density and time.

15p vimclaren 20-10-2022 5 2   Download

Microstructural changes of an OPC cement paste after being exposed at various elevated temperatures and further rehydration have been evaluated using 29Si MAS-NMR. Thermogravimetry and XRD are also employed to complement the information. NMR studies of cement paste exposed to high temperatures demonstrate a progressive transformation of C-S-H gel that leads at 450◦C, to a modified C-S-H gel. For temperatures above 200◦C to a progressive formation of a new nesosilicate.

11p christian2605 10-10-2019 21 0   Download

The results show that ultimate strength under static loading can not be used as a quality criterion for zirconium alloys welds. Increased shielding gas flow rate does not allow to protect weld metal totally and contributes to defect formation without using special nozzles. Several types of imperfections of the welds have been found, but the major problem is branching microcracks on the surface of the welds.

8p minhxaminhyeu3 12-06-2019 17 0   Download

Microstructural analysis indicated that there was no noticeable change in the microstructure of the oxide corresponding to water chemistry changes within the test duration of 100 days (pretransition stage) and no significant difference in the overall thickness of the oxide layer. Equiaxed grains with nano-size pores along the grain boundaries and microcracks were dominant near the water/oxide interface, regardless of water chemistry conditions. As the metal/oxide interface was approached, the number of pores tended to decrease.

9p minhxaminhyeu3 25-06-2019 8 1   Download