Search results for "Civil Engineering"
showing 10 items of 1216 documents
Optimization of the Surface Roughness Equation obtained by Al7136 End-Milling
2017
The aim of this paper is to optimize the regression equation of the surface roughness obtained by 7136 aluminium alloy machined by end-milling process. The surface roughness is dependent on certain process parameters, which can vary, causing in this way variations of the surface quality. The research method used in this paper is the experiment and the Taguchi design of experiment. The experiment was performed using an experimental stand, in which every step to get the purpose, is presented. The measurements were made using a portable surface roughness tester. In the first part of the paper the influence percentage of the involved parameters in the machining process, was determined. Then, a …
Numerical-Experimental Study Regarding the Single Point Incremental Forming Process
2021
The present paper proposes a numerical-experimental comparative study on the single point incremental forming process. A DC04 steel sheet with a thickness of 0.6 mm was used for both the numerical simulation using the finite element method and the experimental research. The type of trajectory used was a spiral trajectory and the finished part obtained was a truncated cone-shaped part. The analysis program used for simulation was Ls-Dyna. The simulations were performed in several variants: with a fixed mesh and with an adaptive mesh, using two different element formulations: 25 (Belytschko-Tsay formulation with thickness stretch) and -16 (fully integrated shell element modified for higher ac…
Curvilinear constraints for free form deformations on subdivision surfaces
2010
This paper presents a method to deform a subdivision surface with curvilinear constraints. It combines an intuitive free form deformation with a Loop subdivision algorithm. The main advantage of this method of deformation is that it uses only vertices of an object and satisfies the geometrical constraints provided by the user. It permits us to control the final shape of the deformed object, defining the range (i.e. the impact) of the deformation before applying it. The deformation takes into account the Loop properties to follow the subdivision scheme, allowing the user to fix some curvilinear constraints at the subdivision level he works on and to render the final object at the level he wa…
Experimental research regarding the study of surface quality of aluminum alloys processed through milling
2017
The aim of this paper is to present the necessary steps to conduct a design of experiment with application on the aluminum alloy surface quality obtained by end-milling process. The machined surface quality is influenced by the cutting process parameters, and especially by their variation. The research methods used in this paper are the Taguchi method - to determine the cutting parameters influence, on the surface quality, and the full factorial design of experiment to confirm the results obtained by Taguchi’s method and to determine the percentage of the parameters influence involved in the process.
Study of the cutting process parameters that influence the surface quality machined by end milling of the aluminum alloy
2019
This research aims to carry out an elaborate experiment by witch resulting in relevant conclusions that have practical applicability in the aeronautical industry. The surface roughness measured transversely and longitudinally on the feed motion direction of the cutting tool constitutes the dedicated objective function on which the study was conducted in this case. The end milling was chosen of an aluminum alloy used explicitly in the aeronautical industry. The actual experiments were carried out in the only aeronautical industry in Romania carrying out these types of machining and were made according to the methodology with rigorous experimental planning of the research. The experimental pl…
Failure Analysis of a Humeral Shaft Locking Compression Plate—Surface Investigation and Simulation by Finite Element Method
2019
A case study of a failed humeral shaft locking compression plate is presented, starting with a clinical case where failure occurred and an implant replacement was required. This study uses finite element method (FEM) in order to determine the failure modes for the clinical case. Four loading scenarios that simulate daily life activities were considered for determining the stress distribution in a humeral shaft locking compression plate (LCP). Referring to the simulation results, the failure analysis was performed on the explant. Using fracture surface investigation methods, stereomicroscopy and scanning electron microscopy (SEM), a mixed mode failure was determined. An initial fatigue failu…
Surface Reflectance: An Optical Method for Multiscale Curvature Characterization of Wear on Ceramic–Metal Composites
2020
Surface gradient characterization by light reflectance (SGCLR) is used for the first time for multiscale curvature calculations and discrimination of worn surfaces on six damaged ceramic&ndash
Study of aortic dissections treatment. Segmentation, simulation and valiadation of surgical results
2019
Nowadays, Computational Fluid Dynamics (CFD) it’s seen as the new trend in the management of aortic pathologies. Together with visualization capabilities of cardiovascular magnetic resonance (CMR) and computed tomography (CT) imaging, real time segmentation (volumetric) models further used as meshes in Computational Fluid Dynamic supply to the clinicians an innovative and extensive decision-making system. In the present paper, we identified and analysed the clinical indicators (lumens diameters, fenestrated area and blood volume) monitored by clinicians to evaluate the patient’ condition before and after the intervention. In order to achieve the targeted aims, we used CT scans as input data…
SUSTAINABLE ARCHITECTURE: THE ECO-EFFICIENCY EARTH CONSTRUCTION
2017
The appropriate choice of building materials can contribute decisively to reduce the energy consumption of the building sector. The increasing worries for the environmental impact of construction materials is witnessed by a lot of studies The mentioned worries has brought again the attention towards natural materials. The use of more sustainable construction materials and construction techniques represent a major contribution to the eco-efficiency of the construction industry and thus to a more sustainable development. Within this frame the renewed interest for a natural material such as the rammed earth is included; the interest has been in continuous growth from the 80s till today. The ra…
Building Energy Performance: A LCA Case Study of kenaf-fibres insulation board
2008
Abstract The paper presents a life cycle assessment of a kenaf-fibre insulation board following the international standards of the ISO 14040 series. Each life-cycle step has been checked, from kenaf production and board manufacture by an Italian firm, to use and disposal. The aim is to assess the board eco-profile and to compare, on the basis of a life-cycle approach, the energy and environmental benefits and drawbacks related to its employment into a typical residential dwelling. A comparison among various insulating materials has been carried out. The study focuses also on processes and input materials which cause the main environmental impacts of the product, and points out critical issu…