Experimental Study of Single-Lap, Hybrid Joints, Made of 3D Printed Polymer and Aluminium Adherends

This paper presents the results of an experimental study into single-lap joints. One part of the joint was made as a 3D printed polymer and had cylindrical tenons, while the other part was made of an aluminium flat bar having mortises whose diameter and distribution corresponded to the polymer tenons. In addition to the mechanical joint, a layer of double-sided VHB (Very High Bond) adhesive tape was also placed in the lap, thus creating a hybrid joint. In total, 80 specimens were made, which were divided into four groups: A—specimens with one tenon of different diameters, B—specimens with different number of tenons of the same diameter, C—specimens characterised by multi-stage operation and R—reference specimens, connected only by double-sided adhesive tape. The joints were subjected to uniaxial tensile tests. The force–displacement characteristics obtained and the energy required, up to the point of the failure of the joints, have been analysed in this paper. The four and six-stage joints designed can significantly increase the safety of the structures in which they will be used.

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The tensile behaviour of biaxial and triaxial braided fabrics

Journal of Industrial Textiles ◽

10.1177/1528083716654469 ◽

2016 ◽

Vol 47 (8) ◽

pp. 2184-2204 ◽

Cited By ~ 9

Author(s):

Duchamp Boris ◽

Legrand Xavier ◽

Soulat Damien

Keyword(s):

Mechanical Properties ◽

Experimental Study ◽

Mechanical Behaviour ◽

Tensile Tests ◽

Uniaxial Tensile ◽

Tensile Behaviour ◽

Linear Mass ◽

Double Peak ◽

Specific Behaviour ◽

Braiding Angle

The tensile behaviour of braid reinforcement is classically described by the behaviour of composite elaborated from these reinforcements. Few studies concern the tensile behaviour of braided fabrics. In this paper biaxial and triaxial braids are manufactured on a braiding loom. The evolution of key parameters as linear mass and braiding angle in function of process parameters is presented. Braid reinforcements are characterized in uniaxial tensile. The mechanical behaviour is analysed and compared in function of the braiding angle, but also different kinds of braid are considered. A specific behaviour called “double-peak” is identified for triaxial braids which have a higher braiding angle. The evolution of the braiding angle measured during tensile tests gives a comprehension on the mechanical behaviour of dry braids. Associated with this experimental study, an analytical model is also proposed, to predict mechanical properties of braid reinforcements.

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Experimental Study on Mechanical Properties of Aluminum Alloys under Uniaxial Tensile Tests

International Journal of Technology ◽

10.14716/ijtech.v8i4.9489 ◽

2017 ◽

Vol 8 (4) ◽

pp. 662 ◽

Cited By ~ 2

Author(s):

Olfa Daghfas ◽

Amna Znaidi ◽

Ahmed Ben Mohamed ◽

Rachid Nasri

Keyword(s):

Mechanical Properties ◽

Experimental Study ◽

Aluminum Alloys ◽

Tensile Tests ◽

Uniaxial Tensile

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Future-Oriented Experimental Characterization of 3D Printed and Conventional Elastomers Based on Their Swelling Behavior

Polymers ◽

10.3390/polym13244402 ◽

2021 ◽

Vol 13 (24) ◽

pp. 4402

Author(s):

Klara Loos ◽

Vivianne Marie Bruère ◽

Benedikt Demmel ◽

Yvonne Ilmberger ◽

Alexander Lion ◽

...

Keyword(s):

Tensile Tests ◽

Swelling Behavior ◽

Uniaxial Tensile ◽

Stress And Strain ◽

Experimental Characterization ◽

Synthetic Fuels ◽

Fuel Component ◽

3D Printed ◽

Fuel Components

The present study investigates different elastomers with regard to their behavior towards liquids such as moisture, fuels, or fuel components. First, four additively manufactured materials are examined in detail with respect to their swelling in the fuel component toluene as well as in water. The chemical nature of the materials is elucidated by means of infrared spectroscopy. The experimentally derived absorption curves of the materials in the liquids are described mathematically using Fick’s diffusion law. The mechanical behavior is determined by uniaxial tensile tests, which are evaluated on the basis of stress and strain at break. The results of the study allow for deriving valuable recommendations regarding the printing process and postprocessing. Second, this article investigates the swelling behavior of new as well as thermo-oxidatively aged elastomers in synthetic fuels. For this purpose, an analysis routine is presented using sorption experiments combined with gas chromatography and mass spectrometry and is thus capable of analyzing the swelling behavior multifacetted. The transition of elastomer constituents into the surrounding fuel at different aging and sorption times is determined precisely. The change in mechanical properties is quantified using density measurements, micro Shore A hardness measurements, and the parameters stress and strain at break from uniaxial tensile tests.

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Development of Formability, Microstructure and Martensite Reversion during Intermediate Annealing of Metastable Austenitic Stainless Steel

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.611-612.49 ◽

2014 ◽

Vol 611-612 ◽

pp. 49-55

Author(s):

Philipp Schmid ◽

Mathias Liewald

Keyword(s):

Stainless Steel ◽

Austenitic Stainless Steel ◽

Tensile Tests ◽

Local Heat ◽

Uniaxial Tensile ◽

Intermediate Annealing ◽

Austenitic Phase ◽

Deep Draw ◽

Multi Stage ◽

Metastable Austenitic Stainless Steel

Intermediate annealing is a widely used process to recover formability in multi-stage deep drawing of austenitic stainless steel sheets. A special ability of metastable austenitic stainless steel is the so called strain-induced martensite formation, which causes the TRIP-effect (TRansformation Induced Plasticity). Major issues of intermediate annealing in serial production processes are long annealing times and high costs for annealing equipment and consumed heating energy. One suggestion for optimization of this process made in this paper is to anneal austenitic material only in regions of the part where it is required and to use suitable annealing parameters. This annealing parameters need to be optimized to requirements of follow-up forming processes. Therefor, basic intermediate annealing experiments were accomplished for austenitic grade EN 1.4301 within temperature range of 100-1100°C. Measurements of mechanical properties by uniaxial tensile tests, martensite contents measured by Feritscope and micrographs are showing the development of martensite reversion as well as reconstitution of austenitic phase. Especially 400°C, 600°C and 1000°C were identified as most interesting annealing temperature levels due to formation of carbides and recrystallization. This knowledge can be used as base for further local heat treatment concepts and may enhance, simplify and save costs of intermediate annealing process of deep draw components made of stainless steel.

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Hybrid Adhesive Bonded and Riveted Joints – Influence of Rivet Geometrical Layout on Strength of Joints / Połączenia Hybrydowe Klejowo-Nitowe - Wpływ Geometrii Rozmieszczenia Nitów Na Wytrzymałość Połączeń

Archives of Metallurgy and Materials ◽

10.2478/v10172-012-0126-0 ◽

2012 ◽

Vol 57 (4) ◽

pp. 1127-1135 ◽

Cited By ~ 7

Author(s):

T. Sadowski ◽

E. Zarzeka-Raczkowska

Keyword(s):

Experimental Research ◽

Lap Joints ◽

Image Correlation ◽

Uniaxial Tensile ◽

Uniaxial Tensile Test ◽

Stress Concentrations ◽

Hybrid Joint ◽

Riveted Joints ◽

Hybrid Joints ◽

Deformation Processes

The hybrid adhesive bonded and riveted joints have wider and wider application in different branches of engineering: aerospace, mechanical, civil etc. The hybrid joints’ strength is 1.5 to 3 times higher than only adhesive bonded joints’ strength. The hybrid joints characterize higher reliability during long-term working. In this article we present the influence of rivets’ lay-out geometry on the hybrid adhesive bonded/riveted joints response to mechanical loading. Experimental research was carried using 3-D digital image correlation system ARAMIS. This system enables monitoring of the deformation processes of the hybrid joint specimen up to failure. We analysed the state of deformation of the adhesive bonded double-lap joints reinforced by different numbers of rivets. The hybrid joint specimens were subjected to the uniaxial tensile test. Moreover, the influence of geometry of individual number of rivets’ layout (rivets arranged in one or more rows) for hybrid joint strength was studied. Experimental research was completed and supported by the computer simulations of the whole deformation processes of metal layers (aluminum), adhesive layers and rivets. Numerical simulations were conducted with the ABAQUS programme. The analysis of stress concentrations in different parts of the hybrid joint and their behaviour up to failure were investigated. Finally, the analysis and the comparison of the obtained results confirmed the influence of rivets’ lay-out geometry not only on rivets joints but also on the hybrid adhesive bonded/riveted joints.

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Application of Dic Technique for Monitoring of Deformation Process of Spr Hybrid Joints / Zastosowanie Techniki Dic Do Obserwacji Procesu Deformacji Hybrydowych Połaczen Typu Spr

Archives of Metallurgy and Materials ◽

10.2478/v10172-012-0161-x ◽

2013 ◽

Vol 58 (1) ◽

pp. 119-125 ◽

Cited By ~ 5

Author(s):

T. Sadowski ◽

M. Knec

Keyword(s):

Deformation Process ◽

Load Capacity ◽

Tensile Tests ◽

Lap Joints ◽

Image Correlation ◽

Uniaxial Tensile ◽

Specimen Preparation ◽

Forming Process ◽

Absorption Increase ◽

Dic Technique

Digital Image Correlation (DIC) technique gives possibility to observe deformation process in many applications including self-piercing riveting (SPR) hybrid joint. The hybrid SPR joint consists of simple SPR joint made of two adherends, steel tubular rivet (total length of 5 mm) and an adhesive. The adhesive was applied before piercing process. For specimen preparation two different aluminum alloys were used: 2024 and 5005 (2mm thickness both) with tensile strength 400 and 160MPa, respectively. For better understanding of joint forming process and to allow DIC strains observation during the joint creation, a special holder was designed with precisely polished die. The tests were performed by application of the 100kN servo-hydraulic machine, which recorded time, load, displacement and was synchronized with the DIC system. The joint forming process was carried out with 2 mm/min constant speed. During piercing process rivet and upper surface of the adherend were observed and the major strain states were estimated. The uniaxial tensile tests of single lap joints (SLJ) up to the final failure were performed and the displacements and the strains were recorded. In particular the rivet deformation was observed also during the whole loading process. The hybrid SPR joints are very effective, because the load capacity and energy absorption increase more than 1.5 times in comparison to the simple SPR joints.

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Optimization of Manufacturing Parameters and Tensile Specimen Geometry for Fused Deposition Modeling (FDM) 3D-Printed PETG

Materials ◽

10.3390/ma14102556 ◽

2021 ◽

Vol 14 (10) ◽

pp. 2556

Author(s):

Arda Özen ◽

Dietmar Auhl ◽

Christina Völlmecke ◽

Josef Kiendl ◽

Bilen Emek Abali

Keyword(s):

Mechanical Properties ◽

Fused Deposition Modeling ◽

Tensile Tests ◽

Tensile Specimen ◽

Careful Examination ◽

Uniaxial Tensile ◽

Fused Deposition ◽

Design Flexibility ◽

Deposition Modeling ◽

3D Printed

Additive manufacturing provides high design flexibility, but its use is restricted by limited mechanical properties compared to conventional production methods. As technology is still emerging, several approaches exist in the literature for quantifying and improving mechanical properties. In this study, we investigate characterizing materials’ response of additive manufactured structures, specifically by fused deposition modeling (FDM). A comparative analysis is achieved for four different tensile test specimens for polymers based on ASTM D3039 and ISO 527-2 standards. Comparison of specimen geometries is studied with the aid of computations based on the Finite Element Method (FEM). Uniaxial tensile tests are carried out, after a careful examination of different slicing approaches for 3D printing. We emphasize the effects of the chosen slicer parameters on the position of failures in the specimens and propose a simple formalism for measuring effective mechanical properties of 3D-printed structures.

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Characterization of PLA/TPU composite filaments manufactured for 3D printing with FDM

Journal of Thermoplastic Composite Materials ◽

10.1177/08927057211062561 ◽

2021 ◽

pp. 089270572110625

Author(s):

Ajay Jayswal ◽

Sabit Adanur

Keyword(s):

3D Printing ◽

Fused Deposition Modeling ◽

Thermoplastic Polyurethane ◽

Tensile Tests ◽

Optical Microscope ◽

Mechanical Analysis ◽

Uniaxial Tensile ◽

Scanning Calorimetry ◽

Fused Deposition ◽

3D Printed

Polylactic acid (PLA) and thermoplastic polyurethane (TPU) were mixed in different proportions and extruded through twin-screw and single-screw extruders to obtain composite filaments to be used for 3D printing with fused deposition modeling (FDM) method. The properties of the filaments were characterized using uniaxial tensile tests, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), rheology, polarized optical microscope (POM), and scanning electron microscope (SEM). 3D printed samples from composite filaments were tested using dynamic mechanical analysis (DMA). It was found that the tensile strength and modulus of the filaments decrease while elongation at break increases with the increasing TPU content in the composite. The analysis also showed a partial miscibility of the polymer constituents in the solution of composite filaments. Finally, a flexible structure, plain weave fabric, was designed and 3D printed using the composite filaments developed which proved that the filaments are well suited for 3D printing.

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Experimental, Computational, and Dimensional Analysis of the Mechanical Performance of Fused Filament Fabrication Parts

Polymers ◽

10.3390/polym13111766 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1766

Author(s):

Iván Rivet ◽

Narges Dialami ◽

Miguel Cervera ◽

Michele Chiumenti ◽

Guillermo Reyes ◽

...

Keyword(s):

Dimensional Analysis ◽

Mechanical Performance ◽

Cost Savings ◽

Acrylonitrile Butadiene Styrene ◽

Tensile Tests ◽

Uniaxial Tensile ◽

Zone Model ◽

Key Factors ◽

Fused Filament Fabrication ◽

3D Printed

Process parameters in Additive Manufacturing (AM) are key factors in the mechanical performance of 3D-printed parts. In order to study their effect, a three-zone model based on the printing pattern was developed. This modelization distinguished three different zones of the 3D-printed part, namely cover, contour, and inner; each zone was treated as a different material. The cover and contour zones were characterized via uniaxial tensile tests and the inner zones via computational homogenization. The model was then validated by means of bending tests and their corresponding computational simulations. To reduce the number of required characterization experiments, a relationship between the raw and 3D-printed material was established by dimensional analysis. This allowed describing the mechanical properties of the printed part with a reduced set of the most influential non-dimensional relationships. The influence on the performance of the parts of inter-layer adhesion was also addressed in this work via the characterization of samples made of Polycarbonate Acrylonitrile Butadiene Styrene (ABS/PC), a polymeric material well known for its poor adhesion strength. It was concluded that by using this approach, the number of required testing configurations could be reduced by two thirds, which implies considerable cost savings.

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Deterioration of the Mechanical Properties of FFF 3D-Printed PLA Structures

Inventions ◽

10.3390/inventions6010001 ◽

2020 ◽

Vol 6 (1) ◽

pp. 1

Author(s):

Asahi Yonezawa ◽

Akira Yamada

Keyword(s):

Mechanical Properties ◽

3D Printing ◽

Test Piece ◽

Tensile Tests ◽

Poly Lactic Acid ◽

Uniaxial Tensile ◽

Layer By Layer ◽

Fused Filament Fabrication ◽

Test Pieces ◽

3D Printed

Poly(lactic acid) (PLA) is a biodegradable polymer material used for the fabrication of objects by fused filament fabrication (FFF) 3D printing. FFF 3D printing technology has been quickly spreading over the past few years. An FFF-3D-printed object is formed from melted polymer extruded from a nozzle layer-by-layer. The mechanical properties of the object, and the changes in those properties as the object degrades, differ from the properties and changes observed in bulk objects. In this study we evaluated FFF-3D-printed objects by uniaxial tensile tests and four-point flexural tests to characterize the changes of three mechanical properties, namely, the maximum stress, elastic modulus, and breaking energy. Eight types of test pieces printed directly by an FFF 3D printer using two scan patterns and two interior fill percentages (IFPs) were tested by the aforesaid methods. The test pieces were immersed in saline and kept in an incubator at 37 °C for 30, 60, or 90 days before the mechanical testing. The changes in the mechanical properties differed largely between the test piece types. In some of the test pieces, transient increases in strength were observed before the immersion degraded the strength. Several of the test piece types were found to have superior specific strength in the tests. The results obtained in this research will be helpful for the design of PLA structures fabricated by FFF 3D printing.

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