A promising substitute for regular concrete is geopolymer concrete. Engineering mechanical parameters of geopolymer concrete, including compressive strength, are frequently measured in the laboratory or in-situ via experimental destructive tests, which calls for a significant quantity of raw materials, a longer time to prepare the samples, and expensive machinery. Thus, to evaluate compressive strength, non-destructive testing is preferred. Therefore, the objective of this research is to develop an artificial neural network model based on the results of destructive and non-destructive tests to assess the compressive strength of geopolymer concrete without needing further destructive tests. According to the artificial neural network analysis developed in this study, the compressive strength of geopolymer concrete can be predicted rather accurately by combining the results of the non-destructive with R 2 of 0.9286.

The current study employs the finite element method to compare stress concentration pertaining to a graphite / epoxy rectangular laminated composite plate that possess holes in different shapes. The hole enables redistributing in-plane stresses, impacts the stress concentration factor (SCF), and focuses maximum stress near the hole. The ANSYS program has been designed to be employed for parametric studies pertaining to plates that have a hole under uniaxial in-plane load. Analysis was done for angle-ply, four-layered symmetrically laminated rectangular plates that include different stacking sequences ± θ.

The attention towards seismic mitigation using passive control systems has increased significantly over the last few decades to reduce earthquake demands and achieve the required performance objectives. Nowadays, friction pendulum bearings have proven efficient in mitigating regular RC structures subjected to a wide range of earthquakes. Nonetheless, limited studies were dedicated to investigating the performance and efficiency of this type of isolation system utilized in RC structures with various types of vertical irregularities. Besides, comprehensive parametric assessments that investigate the behavior of structures supported on friction pendulum bearings subjected to pulse-like and non-pulse-like earthquakes are scarce. Thus, this study aims to assess the behavior of RC frames equipped with friction pendulum isolators under different types of earthquakes. In the context of the paper, three types of vertical irregularities, known as soft-story, heavy-story, and stepped structures, will be modeled and investigated. Moreover, the outcomes of these buildings will be benchmarked to a regular model to illustrate the efficiency of the selected isolation systems. Furthermore, the performance of the base-isolated buildings with friction pendulum isolators subjected to pulse-like and non-pulse-like earthquakes will be reported. In general, the study results have shown that pulse-like earthquakes exhibited higher values than non-pulse-like earthquakes for the different responses of the structures at the periods of 2.5 and 3 and the damping ratios of 15%, 20%, and 25%. Doi: 10.28991/CEJ-2022-08-09-05 Full Text: PDF