Eksperimentalno podprta numerična analiza vijačenih spojev iz armirane plastike : diplomska naloga

Grudnik, Darjan (author), Bosiljkov, Vlatko (mentor), Antolinc, David (co-mentor)

Namen diplomske naloge je predstaviti kompozitne materiale ter izvesti numerično analizo enojnih vijačenih spojev iz armirane plastike. Prednosti kompozitov, natančneje armirane plastike, se kažejo v visoki trdnosti v kombinaciji z majhno prostorninsko težo. Numerični model, izdelan v okviru te diplomske naloge, v programskem okolju Abaqus, je nekoliko preveč poenostavljen za kompleksno analizo, ki bi lahko opisala porušitev spoja. Model nam omogoča opis linearnega dela deformacij obravnavanega spoja od začetka obremenjevanja do točke, kjer je dosežena trdnost materiala. Za celoten opis obnašanja spoja bi bilo potrebno v nadaljevanju upoštevati še mehaniko loma. Med eksperimentalnimi in numeričnimi rezultati je prišlo do odstopanja zaradi poenostavitve geometrije vijaka in definirane popolne vpetosti, ki v realnosti ni mogoča. Največja pomanjkljivost modela pa je definicija materiala, v kateri ni zajeta mehanika loma, ki je tudi glavni razlog za večje odstopanje rezultatov. V primerih preizkušancev, pri katerih sta bili obremenitev in deformacija večji, oziroma je bil odmik vijaka od roba preizkušanca velik, je prišlo do večjega odstopanja rezultatov. Primeri preizkušancev z manjšimi obremenitvami in deformacijami oziroma manjšimi robnimi razdaljami pa so dajali rezultate, ki so bili v inženirskem smislu popolnoma skladni z linearnim delom rezultatov eksperimentalne analize. Armirana plastika je material z ogromno potenciala, ki bo v polni meri izkoriščen, ko bodo na voljo tudi standardi, ki bodo inženirju nudili podporo pri izbiri in uporabi tega materiala.

• Language: Slovenian
• Keywords: kompoziti, armirana plastika, vijačeni spoji, numerična analiza, natezna obremenitev
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FGG - Faculty of Civil and Geodetic Engineering
• Publisher: [D. Grudnik]
• Year: 2020
• PID: 20.500.12556/RUL-120134
• UDC: 624.04+624.07(497.4)(043.2)
• COBISS.SI-ID: 44970243
• Publication date in RUL: 16.09.2020

Secondary language

• Language: English
• Title: Experimentally supported numerical modelling of single bolt lap FRP plate connection : graduation thesis

Abstract

The purpose of this paper is to present composite materials, specifically fiber reinforced polymers or FRP and to carry out a numerical analysis on a single bolt FRP lap joint. The main advantage of FRP elements comes from their high strength with a combination of low mass. Numerical model that was prepared in software Abaqus proved itself to be valid when trying to simulate linear behaviour of experiments where strains, stresses and distances between the bolt and the edge are not too large. Some simplifications regarding the geometry and boundary conditions of the model were made during the experiment conduction. The numerical model is completely valid only until the appearance of the first smallest fracture or until the ultimate strength of an individual fiber is achieved. To improve the accuracy of the model within the linear range or to even describe the nonlinear behaviour, the model would need to be upgraded with finite elements which can consider fracture mechanics theory of the material. As this upgrade exceeds the level of the present thesis, I did not continue the extended studying and research into the fracture mechanics of the considered lap joint. FRP elements have a great potential in the future which will only be achieved when there are valid standards and guidelines with simplified expressions for their design.

• Keywords: composites, FRP, single bolted lap joint, numerical analysis, tension load