Effect of Cyclic Heat, Humidity, and Joining Method on the Static and Dynamic Performance of Lightweight Multimaterial Single-Lap Joints

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Sayed A. Nassar ◽  
Kaori Sakai
Keyword(s):  
Relative Humidity ◽  
Load Transfer ◽  
Dynamic Performance ◽  
Load Ratio ◽  
Lap Joints ◽  
Ambient Conditions ◽  
Heat Cycling ◽  
Single Lap Joints ◽  
Glass Fiber Reinforced ◽  
Static Performance

This experimental study investigates the effect of environmental loading and joining methods on the static and dynamic performance of lightweight multimaterial single-lap joints (SLJ). Joint adherend material combinations are divided into two groups; namely, composite-based and steel-based materials that include glass fiber reinforced polymer (GFRP), steel (St), aluminum (Al), and magnesium (Mg). A commercially available adhesive is selected for the study. Investigated joining methods include bonding-only, bolting-only, and hybrid bonding-and-bolting. Static performance is assessed by the load transfer capacity (LTC) of SLJ after they have been subjected to heat cycling at ambient level of relative humidity, or after heat cycling at high relative humidity. Dynamic performance is measured by durability life (in cycles) of SLJ test samples under a fixed dynamic load ratio in a tensile–tensile fatigue test, after they have been subjected to heat cycling and humidity. The cyclic test load fluctuated between 67.5% and 75% of the static LTC at ambient condition. Sample finding includes the significant effect of heat cycling at an ambient humidity level; it has tripled the LTC of bonded-only composite-to-composite SLJ, relative to their baseline LTC at ambient conditions. Detailed discussion of the results, observations, and conclusions are presented in this paper.

Effect of Heat Cycling and Joining Method on the Mechanical Performance of Multi-Material Single Lap Joints

2015 ◽  
Author(s):  
Kaori Sakai ◽  
Sayed A. Nassar
Keyword(s):  
Load Transfer ◽  
Static Load ◽  
Mechanical Performance ◽  
Dynamic Performance ◽  
Lap Joints ◽  
Bolted Joints ◽  
Fiber Reinforced Polymer ◽  
Single Lap Joints ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced

In this experimental study, both environmental effects and various joining methods are investigated for their impact on the static and dynamic performance of multi-material lightweight single lap joints (SLJ). Adherends are conveniently divided into either composite-based or steel-based lightweight materials that include glass fiber reinforced polymer (GFRP), steel (St), aluminum (Al), or magnesium (Mg). A commercially available adhesive is selected for bonded-only and hybrid bonded-and-bolted joints. Changes in joint static load transfer capacity (LTC) and durability life are investigated for bonded-only, bolted-only, and hybrid bonded-and-bolted joints. Cyclic temperature profile fluctuates between 20° C and 80° C at a constant relative humidity (RH) level of either 20 % or 85 %. Effect on durability life is also studied under a cyclic load that fluctuates between 67.5 % and 75 % of the static load transfer capacity at ambient condition. Detailed discussion of the results, observations, and conclusions are presented in this paper.

Directly bonded single lap joints of SiCp/AA2124 composite with glass fiber-reinforced polypropylene: Hole drilling effects on lap shear strength and out-of-plane impact response

2021 ◽  
pp. 002199832110316
Author(s):  
Nahit Öztoprak
Keyword(s):  
Glass Fiber ◽  
Matrix Composite ◽  
Lap Joints ◽  
Hole Drilling ◽  
Fiber Reinforced ◽  
Single Lap Joints ◽  
Lap Shear ◽  
Glass Fiber Reinforced ◽  
Out Of Plane ◽  
The Impact

Joining dissimilar materials to achieve lightweight design and energy efficiency has been increasingly popular. A joint formed by components of particle-reinforced metal and polymer matrix composite combines the merits of both materials. This paper is mainly focused on the research of the tensile lap shear and impact behavior of the dissimilar single-lap joints (SLJs) between SiCp/AA2124 composite and glass fiber-reinforced polypropylene (PP). The effects of out-of-plane loading applied from different surfaces of SLJs on impact responses are evaluated. Hot pressing technique is introduced to manufacture metal/polymer assembly without using any adhesive. The hole drilling effect is investigated with the idea that it may provide weight reduction and also increase the strength of the dissimilar SLJs. The results indicate that the dissimilar SLJs show more Charpy impact strength when the impact is performed on the metal-matrix composite (MMC). Mechanical properties of SLJs are adversely affected by a drilled hole in the MMC adherend.

Effect of Adhesive Nano-Additives on Static Load Transfer Capacity and Failure Mode of Bonded Steel-Magnesium Single Lap Joints

2015 ◽  
Author(s):  
Sayed A. Nassar ◽  
Kassem Moustafa ◽  
Zhijun Wu ◽  
Demetrios Tzelepis
Keyword(s):  
Failure Mode ◽  
Load Transfer ◽  
Lap Joints ◽  
Mode Analysis ◽  
Paper Test ◽  
Single Lap Joints ◽  
Nano Powder ◽  
Failure Mode Analysis ◽  
Particulate Size ◽  
20 Nm

An experimental procedure and test setup is used for investigating effect of using nanoparticle additives to the adhesive on the load transfer capacity (LTC) of bonded magnesium (Mg)-steel (St) single lap joints (SLJ). Investigated variables include the nano-powder material (Alumina vs. Silica), particulate size (20 nm vs. 80 nm), and concentration in the adhesive (2.5% wt. vs 5.0 % wt.). Two different levels of surface roughness on the bonded area are used; namely, sanding the bond area with G60 or G180 sand paper. Test data and SEM failure mode analysis are provided.

Effect of Autoclave Heating and Cooling Rates on Adhesively Bonded Lightweight Material Joints

2017 ◽  
Author(s):  
Sayed A. Nassar ◽  
Marcello Tardito ◽  
Giovanni Belingardi
Keyword(s):  
Load Transfer ◽  
Peel Strength ◽  
Lap Joints ◽  
Adhesively Bonded ◽  
Lightweight Material ◽  
Single Lap Joints ◽  
Heating And Cooling ◽  
Film Adhesive ◽  
Temperature Ramp ◽  
Polyurethane Film

This study investigates the effect of the rate of autoclave heating and cooling on the performance of bonded lightweight material single lap joints (SLJ) after they have been heat cycled at high relative humidity. Two different temperature ramp rates are used for the autoclave bonding of test joints. Joint performance is assessed in terms of the load transfer capacity (LTC) and the corresponding failure mode in a tensile-shear test. Three different combinations of Aluminium and Magnesium adherends are used in test samples using aliphatic polyether (polyurethane) film adhesive. The effect of heating rate on the peel strength of cured adhesive is also investigated. Data analysis and discussion are provided.

Effect of Cure Temperature and Pressure on Autoclave-Bonded Polycarbonate Single Lap Joints

2016 ◽  
Author(s):  
Sayed A. Nassar ◽  
Shraddha Jagatap ◽  
Marcello Tardito
Keyword(s):  
Load Transfer ◽  
Mechanical Performance ◽  
Lap Joints ◽  
Mode Analysis ◽  
Single Lap Joints ◽  
Failure Data ◽  
Failure Mode Analysis ◽  
Temperature And Pressure ◽  
Cure Temperature ◽  
Joint Load

This study investigates the effect of cure temperature and pressure on the mechanical performance of autoclave-bonded single lap joints (SLJ). Joint load transfer capacity (LTC) and failure mode analysis are provided. Test joints are made of two polycarbonate lexan adherends that are autoclave-bonded together using aliphatic polyether (Polyurethane) film adhesive (Huntsman PE399). Two levels of cure pressure and cure temperature are investigated, for their effect on joint load transfer capacity and failure. Data analysis and discussion are provided.

DYNAMIC PERFORMANCE OF ADHESIVELY BONDED SINGLE LAP JOINTS WITH DIFFERENT FIBER ANGLE ORIENTATIONS OF ADHERENDS

2021 ◽  
Author(s):  
S. BUSE KARAAHMET ◽  
FERHAT KADIOGLU
Keyword(s):  
Adhesive Bonding ◽  
Flexural Rigidity ◽  
Dynamic Performance ◽  
Adhesive Layer ◽  
Lap Joints ◽  
Adhesive Film ◽  
Single Lap Joints ◽  
Vibration Technique ◽  
Materials Used ◽  
Fixed End

This work aims to investigate the dynamic response of the adhesive bonding of Single Lap Joints (SLJs) using a free vibration technique. For this purpose, the joints with fixed-end conditions were subjected to the vibration test, and the results were compared with the numerical ones which were obtained from the Finite Element Method (FEM) via the ANSYS package program. The materials used in this study are an adhesive film, AF163 2K produced by 3M, and adherends, manufactured from a glass reinforced polymer matrix composite, produced by Hexcel. While four different adherends with different fiber orientations were used, the thickness of the adhesive layer in bonded region was kept constant, 0.2 mm. In doing so, the main concentration was given to the adherends as the energy dissipation was believed to come mainly from them. The main objective was to get high damping values without compromising any decrease in the structural performance of the joints. The experimental natural frequency, flexural rigidity and damping values of the joints were obtained as a parameter of the different adherend types. The results were also validated using numerical modal analysis.

Effect of Adhesive Nanoparticle Enrichment on Static Load Transfer Capacity and Failure Mode of Bonded Steel–Magnesium Single Lap Joints

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Sayed A. Nassar ◽  
Zhijun Wu ◽  
Kassem Moustafa ◽  
Demetrios Tzelepis
Keyword(s):  
Failure Mode ◽  
Load Transfer ◽  
Lap Joints ◽  
Mode Analysis ◽  
Paper Test ◽  
Experimental Procedure ◽  
Single Lap Joints ◽  
Failure Mode Analysis ◽  
Particulate Size ◽  
20 Nm

An experimental procedure and test setup are used for investigating effect of using nanoparticle additives to the adhesive on the load transfer capacity (LTC) of bonded magnesium (Mg)–steel (St) single lap joints (SLJ). Investigated variables include the nanopowder material (alumina versus silica), particulate size (20 nm versus 80 nm), and concentration in the adhesive (2.5 wt.% versus 5.0 wt.%). Two different levels of surface roughness on the bonded area are used, namely, sanding the bond area with G60 or G180 sand paper. Test data and scanning electron microscopy (SEM) failure mode analysis are provided.

Failure Analysis of Composite-Based Lightweight Multimaterial Joints in Tensile-Shear Tests After Cyclic Heat at High-Relative Humidity

2016 ◽  
Vol 139 (4) ◽  
Author(s):  
Kaori Sakai ◽  
Sayed A. Nassar
Keyword(s):  
Relative Humidity ◽  
Failure Analysis ◽  
Load Transfer ◽  
Epoxy Adhesive ◽  
Lap Joints ◽  
High Relative Humidity ◽  
Published Data ◽  
Tensile Shear ◽  
Bonded Composite ◽  
Cyclic Heat

Failure analysis of tensile-shear tested bonded composite-based single lap joints (SLJs) that have been subjected to two different levels of cyclic environmental loading is provided. Each test joint has at least one composite adherend which is made of glass fiber-reinforced polymer (GFRP); the second adherend may be aluminum, magnesium, or GFRP composite, and structural epoxy adhesive is used to join two adherends together for creating test joints. Scanning electron microscope (SEM) and energy dispersive spectrometry (EDS) are utilized to investigate the root cause failure of fractured surfaces that gives an insight into the recently published data that showed a significant effect of the cyclic heat on the static load transfer capacity (LTC) of the same SLJs. The SEM and EDS inspections show that the failure mode shifts from interfacial adhesive failure (ADH) to fiber tear (FT) for the GFRP/GFRP joints that have been exposed to cyclic heat with and without high relative humidity as compared to that at ambient condition. Further, failure analysis and discussion are provided.

Sign in / Sign up

Export Citation Format

Share Document