Curing-Induced Distortion Mechanism in Adhesive Bonding of Aluminum AA6061-T6 and Steels

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
XiaoBo Zhu ◽  
YongBing Li ◽  
GuanLong Chen ◽  
Pei-Chung Wang
Keyword(s):  
Automotive Industry ◽  
Adhesive Bonding ◽  
Elevated Temperatures ◽  
Dissimilar Materials ◽  
Curing Temperature ◽  
Vehicle Body ◽  
Material System ◽  
Adhesive Properties ◽  
Adhesive Fracture ◽  
Strength Constraints

The bonding of dissimilar materials is of primary importance to the automotive industry as it enables designers the freedom to choose from a wide variety of low density materials such as aluminum and magnesium. However, when two dissimilar materials (e.g., aluminum-to-steel) are bonded by curing at elevated temperatures, residual stresses result upon cooling the layered material system to room temperature. Problems such as distortion and fracture of adhesive often emerge in bonding of these dissimilar materials for automotive applications. In this study, the transient distortion of riveted and rivet-bonded aluminum AA6061-T6-to-steels during the curing process was investigated using the photographic method. The influences of temperature, adhesive properties, adherend thickness, adherend strength, and the presence of constraints on the transient distortion and adhesive fracture were evaluated. The peak curing temperature was found to play the most important role in distortion and adhesive fracture, followed by the influence of adherends thickness. In contrast, the other parameters studied such as the adhesive strength, constraints' type, and adherend strength produced a limited effect on distortion. The results provide useful information about vehicle body structure's design in reducing the curing induced distortion.

Experimental Investigation of Residual Stresses in Layered Materials Using Moire´ Interferometry

2002 ◽  
Vol 124 (4) ◽  
pp. 340-344 ◽  
Author(s):  
Keith B. Bowman ◽  
David H. Mollenhauer
Keyword(s):  
Residual Stresses ◽  
Thermal Loading ◽  
Elevated Temperatures ◽  
Dissimilar Materials ◽  
Layered Materials ◽  
Moiré Interferometry ◽  
Moire Interferometry ◽  
Material System ◽  
Interlaminar Stresses ◽  
Free Edges

As two dissimilar materials are bonded or cocured at elevated temperatures, residual stresses result upon cooling the layered material system to room temperature. It is well known that the free edges of composite laminates experience interlaminar stresses during applied mechanical or thermal loading. These stresses are significant and must be understood. Current experimental methods are not capable of determining the residual stresses along free edges where failure is likely to initiate. This paper describes the initial findings of a novel experimental technique that uses moire´ interferometry and material removal to determine the residual stress distribution resulting from elevated temperature processing at the free edges of layered materials.  

Comparison of Bonding Performance for CFRP-SPCC Single Lap Joint Using Adhesives and Rivets

2016 ◽  
Vol 859 ◽  
pp. 45-49
Author(s):  
Ok Hyoung Lee ◽  
Il Teak Lee ◽  
Hee Yong Kang ◽  
Sung Mo Yang ◽  
Jun Young Yim ◽  
...  
Keyword(s):  
Automotive Industry ◽  
Adhesive Bonding ◽  
Recent Trend ◽  
Dissimilar Materials ◽  
Failure Surface ◽  
Lap Joint ◽  
Tensile Shear ◽  
Single Lap Joint ◽  
Bonding Performance ◽  
Metal Materials

The recent trend in automotive industry is characterized by the replacement of existing metal materials with composite ones or the combination of both for lightweight parts. This study 1) created single lap joint specimens of SPCC used for automobile frame and four adhesives; epoxy, urethane, acrylic, mixed (urethane and acrylic) and rivets to bind dissimilar materials of CFRP necessary for weight lightening, and 2) performed a tensile shear test on adhesive bonding versus adhesive bonding with rivets. In summary, this study investigated on the bonding performance of different specimens: bonding strength, shapes of the failure surface, and the effect of rivets on bond strength.

The effect of temperature on the mechanical properties of adhesives for the automotive industry

2010 ◽  
Vol 224 (2) ◽  
pp. 51-62 ◽  
Author(s):  
M D Banea ◽  
L F M da Silva
Keyword(s):  
Automotive Industry ◽  
Adhesive Bonding ◽  
Design Procedure ◽  
Dissimilar Materials ◽  
High Volume ◽  
Effect Of Temperature ◽  
Bulk Specimen ◽  
Fuel Savings ◽  
Industry Applications ◽  
High Volume Production

The application of adhesively bonded joints in structural components made of composite materials for automotive industry applications has increased significantly in recent years and provides many benefits that will ultimately lead to lighter-weight vehicles, fuel savings, and reduced emissions. The principal benefits are design flexibility, opportunity for part consolidation, and joining of dissimilar materials. While much work has been conducted in adhesive bonding for the aerospace industry, the automotive industry does not currently have a full portfolio of processes and methods for evaluating candidate adhesives for use in bonding structural automotive components. Aerospace techniques and materials are not generally applicable, since the automotive industry must be more cognizant of cost and high volume production. In this article, the performances of two different adhesive types, an epoxy and a polyurethane, have been studied through bulk specimen and adhesive joint tests. Results showed that the failure loads of both the bulk test and joint test specimens vary with temperature and this needs to be considered in any design procedure. Also, for the polyurethane adhesive, the single lap joint is sufficient to determine the adhesive shear strength.

scholarly journals A Review on Adhesively Bonded Aluminium Joints in the Automotive Industry

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 730
Author(s):  
Francesca Cavezza ◽  
Matthieu Boehm ◽  
Herman Terryn ◽  
Tom Hauffman
Keyword(s):  
Automotive Industry ◽  
Adhesive Bonding ◽  
Ionic Species ◽  
Adhesively Bonded ◽  
Adhesive Properties ◽  
Effect Of Water ◽  
Filiform Corrosion ◽  
Key Enabling Technologies ◽  
Physical And Chemical ◽  
Adhesively Bonded Joint

The introduction of adhesive bonding in the automotive industry is one of the key enabling technologies for the production of aluminium closures and all-aluminium car body structures. One of the main concerns limiting the use of adhesive joints is the durability of these system when exposed to service conditions. The present article primarily focuses on the different research works carried out for studying the effect of water, corrosive ions and external stresses on the performances of adhesively bonded joint structures. Water or moisture can affect the system by both modifying the adhesive properties or, more importantly, by causing failure at the substrate/adhesive interface. Ionic species can lead to the initiation and propagation of filiform corrosion and applied stresses can accelerate the detrimental effect of water or corrosion. Moreover, in this review the steps which the metal undergoes before being joined are described. It is shown how the metal preparation has an important role in the durability of the system, as it modifies the chemistry of the substrate’s top layer. In fact, from the adhesion theories discussed, it is seen how physical and chemical bonding, and in particular acid-base interactions, are fundamental in assuring a good substrate/adhesive adhesion.

scholarly journals Effect of the Process Parameters on the Adhesive Strength of Dissimilar Polymers Obtained by Multicomponent Injection Molding

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1039 ◽  
Author(s):  
Luciano Pisanu ◽  
Leonardo Costa Santiago ◽  
Josiane Dantas Viana Barbosa ◽  
Valter Estevão Beal ◽  
Marcio Luis Ferreira Nascimento
Keyword(s):  
Adhesive Strength ◽  
Natural Fiber ◽  
Fiber Composite ◽  
Pure Shear ◽  
Central Area ◽  
Dissimilar Materials ◽  
Type I ◽  
Coconut Fiber ◽  
Adhesive Properties ◽  
Experimental Conditions

The growing demand in the consumer market for products with sustainable technologies has motivated new applications using overmolded natural fiber composites. Therefore, studies have been conducted mainly to understand the adhesive properties of overmolded parts. In the present study, a polypropylene (PP) composite with 30% coconut fibers without additives was developed with the aid of a corotating twin screw extruder. Subsequently, a multicomponent injection mold was developed based on the geometry of the ISO 527 type I specimen, in which samples overmolded with PP and PP–coconut-fiber composite, with the overlap in the central area, were obtained to evaluate the adhesive strength of dissimilar materials. The objective of this study was to evaluate the bond between PP and PP–coconut-fiber composite under different processing conditions using an adhesive strength testing device to perform a pure shear analysis. The experimental conditions followed a statistical design considering four factors in two levels and a significance level of 5%. The results indicated that adhesive strength increased significantly as the overlap area increased. It was observed that temperature and injection flow rate were the factors that most contributed to strengthening the bonds of dissimilar materials.

scholarly journals Innovative concepts for the usage of veneer-based hybrid materials in vehicle structures

2021 ◽  
pp. 146442072199839
Author(s):  
DB Heyner ◽  
G Piazza ◽  
E Beeh ◽  
G Seidel ◽  
HE Friedrich ◽  
...  
Keyword(s):  
Steel Strip ◽  
High Energy ◽  
The Body ◽  
Vehicle Body ◽  
Material System ◽  
Laminated Veneer Lumber ◽  
Hybrid Beam ◽  
Bending Load ◽  
The Impact ◽  
Very High

A promising approach for the development of sustainable and resource-saving alternatives to conventional material solutions in vehicle structures is the use of renewable raw materials. One group of materials that has particular potential for this application is wood. The specific material properties of wood in the longitudinal fiber direction are comparable to typical construction materials such as steel or aluminum. Due to its comparatively low density, there is a very high lightweight construction potential especially for bending load cases. Structural components of the vehicle body are exposed to very high mechanical loads in the case of crash impact. Depending on the component under consideration, energy has to be absorbed and the structural integrity of the body has to be ensured in order to protect the occupants. The use of natural materials such as wood poses particular challenges for such applications. The material characteristics of wood are dispersed, and depend on environmental factors such as humidity. The aim of the following considerations was to develop a material system to ensure the functional reliability of the component. The test boundary conditions for validation also play a key role in this context. The potential of wood–steel hybrid design based on laminated veneer lumber and steel was investigated for use in a component subjected to crash loads such as the door impact beam. The chosen solution involves a separation of functions. A laminated veneer lumber-based beam was hybridized with a steel strip on the tension side. The steel strip was designed to compensate the comparatively low elongation at fracture of the wood and to ensure the integrity of the beam. The wooden component was designed for high energy absorption due to delamination and controlled failure during the impact, while maintaining the surface moment of inertia, i.e. the bending stiffness of the entire component. This approach was chosen to ensure the functional safety of the component, avoid sudden component failure and utilize the high potential of both materials. The tests carried out provided initial functional proof of the chosen solution. The hybridization achieved significantly higher deformations without sudden failure of the beam. In addition, bending capabilities were increased significantly compared to a beam without hybridization. In comparison with a state-of-the-art steel beam, the hybrid beam was not able to achieve the maximum deformation and the target weight of the hybrid beam. Further optimization of the hybrid beam is therefore necessary.

scholarly journals Strengthening epoxy adhesives at elevated temperatures based on dynamic disulfide bonds

2020 ◽  
Vol 1 (9) ◽  
pp. 3182-3188
Author(s):  
Hsing-Ying Tsai ◽  
Yasuyuki Nakamura ◽  
Takehiro Fujita ◽  
Masanobu Naito
Keyword(s):  
Glass Transition ◽  
Disulfide Bonds ◽  
Epoxy Resins ◽  
Elevated Temperatures ◽  
Adhesive Properties ◽  
Epoxy Adhesives ◽  
Transition Points ◽  
Increasing Temperature

Epoxy resins incorporating aromatic disulfide bonds demonstrated improved adhesive properties with increasing temperature below their glass transition points.

scholarly journals Connections between steel and aluminium using adhesive bonding combined with self-piercing riveting

2018 ◽  
Vol 183 ◽  
pp. 04010 ◽  
Author(s):  
Matthias Reil ◽  
David Morin ◽  
Magnus Langseth ◽  
Octavian Knoll
Keyword(s):  
Adhesive Bonding ◽  
Numerical Models ◽  
Dissimilar Materials ◽  
Material Design ◽  
Connected Components ◽  
Adhesively Bonded ◽  
Test Setup ◽  
Vehicle Crash ◽  
Component Test ◽  
Development And Validation

The multi-material design of modern car bodies requires joining technologies for dissimilar materials. Adhesive bonding in combination with self-piercing riveting is widely used for joining steel and aluminium structures. To guarantee crashworthiness and reliability of a car body, accurate and effcient numerical models of its materials and connections are required. Suitable component test setups are necessary for development and validation of such models. In this work, a novel test setup for adhesively bonded and point-wise connected components is presented. Here, load combinations comparable to a vehicle crash are introduced into the connections. The developed setup facilitates successive failure of multiple connections and enables a broad validation of numerical connection models.

A Coupled Temperature-Displacement Numerical Analysis of Hydraulic Press Workspace

2016 ◽  
Author(s):  
Jakub Jirasko ◽  
Antonin Max ◽  
Radek Kottner
Keyword(s):  
Numerical Analysis ◽  
Computational Model ◽  
Automotive Industry ◽  
Elevated Temperatures ◽  
Compressive Force ◽  
Hydraulic Press ◽  
Metallic Materials ◽  
Pressing Force ◽  
Stress Criterion ◽  
The Press

The analysis is performed on a hydraulic press which is intended for use in the automotive industry and is a part of a production line. The final phase of manufacture of interior and acoustic parts takes place in this press. These interior and acoustic parts are made of sandwich fabric which is inserted into the heated mould of the press and by treatment with a defined pressure (or, more precisely, a defined compression) and temperature, it is formed into its final shape. This press has a frame with four columns and it is not preloaded. Two double acting hydraulic cylinders placed on an upper cross beam exert the compressive force. Due to continuously increasing demands on the accuracy and quality of products not only in the automotive industry, it is necessary to ensure compliance with the accuracy of certain values of machine operation. Especially in this case, the value of accuracy substantially depends on the clamping plates of the press, for which a certain value of flatness is required, both at room temperature and at elevated temperatures. To achieve this accuracy, it is necessary to guarantee sufficient stiffness of the machine to resist the pressing force with the smallest deformation possible. Another crucial factor affecting the accuracy of the machine is heating of the heated clamping plates. Unequal heating of parts of the frame causes additional deformation that has to be quantified and eliminated. The main aim was to verify the design of the press by numerical computation and gather knowledge for modifying the topological design of the press so that it fulfils the required customer parameters of flatness and parallelism for different types of loading. A computational model of the press was created for the numerical solution of a coupled temperature-displacement numerical analysis. The analysis was performed using the finite element method in Abaqus software. The press is symmetrical in two orthogonal planes and the load of the press is considered to be centric. On the basis of these two factors it was possible to carry out the analysis by considering only a quarter of the press. The analysis was used to investigate the effects of static and combined loads from the pressing force and heat on the press. The influence of a cooling circuit located in the press frame for the reduction of frame deformation (and deformation of clamping plates) was investigated. Contacts were defined among individual parts to ensure the computational model had characteristics as close as possible to the real press. The analysis was solved as stationary, on the basis that the cooling of the tool between individual pressing cycles is negligible. The insulating plates are made of a particulate composite material which was considered to have isotropic properties depending on the temperature. For strength evaluation of composite materials all individual components of the stress tensor were examined according to the maximum stress criterion. Hook’s law was considered to be valid for the metallic materials. Von Mises criterion was used to evaluate the strength of the metallic materials. The geometry of the press was discretized using 3D linear thermally coupled brick elements with 8 nodes and full integration (C3D8T). There were approximately 174,000 elements in total. Design procedures for designing a press frame with higher work accuracy (flatness) were proposed with the example of the simplified model of the press table. With these methods it is possible to achieve times higher accuracy than is achieved with conventional method.

Experimental Investigation of Adhesive Bonding for Post‐installed Rebars into Concrete at High Temperatures

2019 ◽  
Author(s):  
Thanyawat Pothisiri ◽  
Pitcha Jongvivatsakul ◽  
Vanichapoom Nantavong
Keyword(s):  
Experimental Investigation ◽  
High Temperatures ◽  
Mechanical Behaviour ◽  
Epoxy Resins ◽  
Adhesive Bonding ◽  
Elevated Temperatures ◽  
Adhesive Bond ◽  
Steel Rebar ◽  
Pull Out ◽  
Embedment Length

<p>The use of post‐installed rebars into existing reinforced concrete structures bonded with epoxy resins was constantly increasing due to the advantage of equivalent or even higher bearing capacities at service temperature, compared with conventional cast‐in‐place rebars. Previous studies have examined the effects of different parameters on the mechanical properties of bonded post‐installed rebars at normal temperature. These studies showed that, for rebar diameter equal to 10 mm, the load bearing capacity increases linearly with the embedment length up to 75 mm. However, upon exposure to high temperatures, the glass transition of epoxy resins may occur and affect the mechanical behaviour of the adhesive bond. Studying the mechanical behaviour of an adhesive anchor at high temperatures is therefore necessary. An experimental investigation is conducted herein to examine the characteristics of the adhesive bonding stress between steel rebar and concrete interface at elevated temperatures using a series of pull‐out tests with varying rebar diameters and embedment lengths.</p>

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