Search results for "Compres"
showing 10 items of 1107 documents
LOAD SUPPORT OF FRC CYLINDERS UNDER COMPRESSION
2000
ABSTRACT The purpose of this research is to look for the optimum structure applied FRC for load support by considering the biomimetic design. For example, cortical bone is made of FRC structures for load support in living bones. Making a start of analysis, the osteon being an structural unit of cortical bone was modelled in filament-wound (FW) cylinder. The first approximation of cortical bone was represented by the densest arrangement of the cylinders to focus on compressive behaviour of osteons. E-glass/epoxy cylinders were applied to specimens. Static compression tests were carried out to evaluate these models. On the osteon model, the smaller ply angle to the longitudinal direction gave…
A Cap-Model for Masonry-Like Material Constitutive Laws
1995
An accurate description of the constitutive behaviour of masonry-like materials is an essential target for obtaining an effective analysis-tool of masonry structures. In this paper an idealized constitutive model of such materials is proposed taking into account some peculiar features of masonry: -i) a limited strength in compression; -ii) a very limited ability to withstand tensile stresses; -iii) a softening behaviour due to a progressive reduction of the tensile strength during a monotonically increasing loading.
Considerations on factors affecting biochar densification behavior based on a multiparameter model
2021
The optimization of upscaled biochar pelleting is limited by lack of knowledge regarding the effects of process parameters. A multiparameter model, coupled to a single pellet press unit, was for the first time applied to biochar production to predict the upscaled biochar pelleting process behavior. The model permits to estimate in a time and cost-effective way how the die friction forces, quantified through the pellet exiting pressure, are affected by the key process parameters. It was observed that to achieve acceptably low exiting pressures (in the order of 100 MPa), it was critical to produce biochar at high temperatures (e.g. 600 °C). Addition of water as a binder is also beneficial, wh…
Experimental and numerical analysis of aluminum-aluminum bolted joints subject to an indentation process
2015
Abstract The increasing interest of the industry (especially automotive, aviation and marine) in the fastener joints (riveted, bolted, etc.) between metallic materials, has re-opened the study on the possibility to improve the performance of the drilled structure using plastic deformation processes. Indentation process, performed before the drilling operation, creates circumferential compression stresses around the hole which increase significantly the mechanical performance of the drilled structures. In this paper, static and the fatigue performances of aluminum–aluminum (AW 6082-T6) single-lap bolted joints are studied. In particular, the study compares the mechanical strength of only dri…
Experimental investigation on compressive behavior of bottle-shaped struts
2011
The goal of this investigation was the experimental verification of the dispersion of compression in bottle-shaped struts. Two typical bottle shapes were generated under load in compression concrete—both drilled and undrilled—and were reinforced concrete prismatic members with loading steel plate having a reduced area with respect to the entire cross section of the members. Axial load, and axial and lateral strains were recorded during the tests to evaluate the effects of key parameters. The comparative analysis of the experimental results showed that: 1) the presence of a hole produces a variation on the stress and strain distribution and a reduction in the load-carrying capacity; 2) the r…
Fibrous reinforced concrete beams in flexure: Experimental investigation, analytical modelling and design considerations
2008
Abstract The flexural behavior of plain and fibrous reinforced concrete (FRC) beams under monotonic and cyclic actions was analysed. Twelve beams were reinforced with top and bottom longitudinal deformed steel bars and transverse steel stirrups. Concrete, having 30 MPa cylindrical strength, was reinforced with hooked steel fibres at a volume percentage of 1%. Beams, 600 mm in length and with a square side cross-section of 150 mm, were tested in flexure using a three point bending test, adopting three different cover thicknesses of 5, 15 and 25 mm, respectively. The results obtained show that the addition of fibers increases the bearing capacity of the beams and ensures more ductile behaviou…
Reactive Powder Concrete Containing Basalt Fibers: Strength, Abrasion and Porosity
2020
The paper presents the test results of basalt fiber impact on a compressive and flexural strength, resistance to abrasion and porosity of Reactive Powder Concrete (RPC). The reasons for testing were interesting mechanical properties of basalt fibers, the significant tensile strength and flexural strength, and in particular the resistance to high temperatures, as well as a relatively small number of RPC tests performed with those fibers and different opinions regarding the impact of those fibers on concrete strength. The composition of the concrete mix was optimized to obtain the highest packing density of particles in the composite, based on the optimum particle size distribution curve acc.…
A Formal Passage From a System of Boltzmann Equations for Mixtures Towards a Vlasov-Euler System of Compressible Fluids
2019
A formal asymptotics leading from a system of Boltzmann equations for mixtures towards either Vlasov-Navier-Stokes or Vlasov-Stokes equations of incompressible fluids was established by the same authors and Etienne Bernard in: A Derivation of the Vlasov-Navier-Stokes Model for Aerosol Flows from Kinetic Theory Commun. Math. Sci., 15: 1703–1741 (2017) and A Derivation of the Vlasov-Stokes System for Aerosol Flows from the Kinetic Theory of Binary Gas Mixtures. KRM, 11: 43–69 (2018). With the same starting point but with a different scaling, we establish here a formal asymptotics leading to the Vlasov-Euler system of compressible fluids. Explicit formulas for the coupling terms are obtained i…
The Reconstruction of Polyominoes from Approximately Orthogonal Projections
2001
The reconstruction of discrete two-dimensional pictures from their projection is one of the central problems in the areas of medical diagnostics, computer-aided tomography, pattern recognition, image processing, and data compression. In this note, we determine the computational complexity of the problem of reconstruction of polyominoes from their approximately orthogonal projections. We will prove that it is NP-complete if we reconstruct polyominoes, horizontal convex polyominoes and vertical convex polyominoes. Moreover we will give the polynomial algorithm for the reconstruction of hv-convex polyominoes that has time complexity O(m3n3).
A fully adaptive multiresolution scheme for image processing
2007
A nonlinear multiresolution scheme within Harten's framework [A. Harten, Discrete multiresolution analysis and generalized wavelets, J. Appl. Numer. Math. 12 (1993) 153-192; A. Harten, Multiresolution representation of data II, SIAM J. Numer. Anal. 33 (3) (1996) 1205-1256] is presented. It is based on a centered piecewise polynomial interpolation fully adapted to discontinuities. Compression properties of the multiresolution scheme are studied on various numerical experiments on images.