Search results for "Lap joint"
showing 10 items of 36 documents
Friction stir welding of stainless steel thin sheets in lap configuration
2013
New research trends for Friction Stir Welding include the use of highly resistant materials as steels and titanium alloys. In the paper a continuum based FEM model for Friction Stir Welding of lap joint made out of thin stainless steel sheets is proposed, that is 3D Lagrangian implicit, coupled, rigid-viscoplastic. The model, whose potential has been analyzed though temperature distribution comparisons, is able to predict temperature, strain and strain rate distributions, with varying process variables. In this way the FEM model can be applied for effective process and tool design.
Joining Ti6Al4V and AISI 304 through friction stir welding of lap joints: experimental and numerical analysis
2014
The results of an experimental and numerical analysis on Friction Stir Welding of dissimilar lap joints made out of AISI304 and Ti-6Al-4 V thin sheets are presented. The mixed joints, welded with varying process parameters, have been characterized from a mechanical and metallurgical point of view. A numerical model able to take into account the behaviour of the two different materials has been used. The numerical results have been utilized to explain the joint properties and the occurring material flow. The effect of the heat input, tilt angle and sheets mutual position has been investigated. It is found that both hooking defects and tunnels may occur with incorrect choice of process parame…
Effect of curing time on the performances of hybrid/mixed joints
2013
Abstract The aim of this work is the study of a mixed method used for the joining of aluminum alloys with glass reinforced polymer’s substrates (in the next GFRP). In particular, the technique of self-piercing riveting (in the next SPR) was applied on a co-cured joint in order to evaluate the influence of the time of inserting the rivet on the mechanical behavior of the mixed joints. Three different joints were realized: adhesive by co-curing technique, mechanical by self piercing riveting (in the next SPR) and a mixed one in which the joining techniques (i.e. adhesive and mechanical) were combined. In particular, to determine the optimum time to insert the rivet, three different times from…
Mechanical and microstructural characterization of friction stir welded skin and stringer joints
2013
A microstructural and mechanical investigation on lap joints welded by friction stir welding and made out of a 7075-T6 stringer and a 2024-T4 skin is presented. In particular, the metallurgical and mechanical properties of joints have been studied at different tool feed rates (V = 35, 50, 100 mm/min) and constant rotation speed (R = 500 r/min). Temperature distributions have been monitored during the process. It is found that in the welded area, the recrystallized zone (nugget) has an average grain size of about 3 µm and exhibits coarsened MgZn2 particles on grain boundaries. The maximum values of microhardness in the welded skin increase with the process temperature, while they just sligh…
Pinned hybrid glass-flax composite laminates aged in salt-fog environment: Mechanical durability
2019
The aim of the present paper is to study the mechanical performance evolution of pinned hybrid glass-flax composite laminates under environment aging conditions. Hybrid glass-flax fibers/epoxy pinned laminates were exposed to salt-spray fog environmental conditions up to 60 days. With the purpose of assessing the relationship between mechanical performances and failure mechanisms at increasing aging time, single lap joints at varying joint geometry (i.e., hole diameter D and hole distance E from free edge) were characterized after 0 days (i.e., unaged samples), 30 days, and 60 days of salt-fog exposition. Based on this approach, the property&ndash
Drop weight tensile impact testing of adhesively bonded carbon/epoxy laminate joints
2012
Abstract Crashworthiness of composite structures is a key issue for the design of lightweight vehicles. In particular the joined parts of the structures must be able to absorb a high amount of energy in order to protect the passengers. In this paper the dynamic behavior of adhesively bonded carbon/epoxy laminate joints is investigated. The adherends are made of unidirectional plies, whose orientations are carefully chosen in order to assess the influence of the adherend mechanical properties on the joint behavior. A drop weight machine has been modified in order to impact specimens under tension. Single lap joints are tested under impact tension at velocities from 1 to 4 m/s. Results of the…
Laboratory Tests for Assessing the Reliability and Durability of Innovative Cold-Glued 3D Glass Building Subcomponents
2020
The paper shows the results of analyses of the behavior of an innovative subcomponent made of two glass shells and a plastic thermal belt interfaced with a resin-based adhesive, in order to define the plastic material–adhesive combination able to guarantee compliance with the requirements related to mechanical strength, thermoacoustic insulation, dimensional stability, material compatibility, and durability. Two different types of ultraviolet (UV)-curing adhesive were used to establish the best plastic–adhesive combination. A study of the mechanical behavior and the reliability over time of the bonded assembly was conducted by performing accelerated weathering tests and tensile tests on 30 …
Experimental and numerical analysis of aluminum-aluminum bolted joints subject to an indentation process
2015
Abstract The increasing interest of the industry (especially automotive, aviation and marine) in the fastener joints (riveted, bolted, etc.) between metallic materials, has re-opened the study on the possibility to improve the performance of the drilled structure using plastic deformation processes. Indentation process, performed before the drilling operation, creates circumferential compression stresses around the hole which increase significantly the mechanical performance of the drilled structures. In this paper, static and the fatigue performances of aluminum–aluminum (AW 6082-T6) single-lap bolted joints are studied. In particular, the study compares the mechanical strength of only dri…
An aging evaluation of the bearing performances of glass fiber composite laminate in salt spray fog environment
2019
The aim of the present paper is to assess the bearing performance evolution of pinned, glass-composite laminates due to environmental aging in salt-spray fog tests. Glass fibers/epoxy pinned laminates were exposed for up to 60 days in salt-spraying, foggy environmental conditions (according to ASTM B117 standard). In order to evaluate the relationship between mechanical failure mode and joint stability over increasing aging time, different single lap joints, measured by the changing hole diameter (D), laminate width (W) and hole free edge distance (E), were characterized at varying aging steps. Based on this approach, the property-structure relationship of glass-fibers/epoxy laminates was a…
Ultrasonic Guided Wave Inspection of Bonded Lap Joints: Noncontact Method and Photoelastic Visualization
2001
The main topic of this paper is the nondestructive inspection of adhesively bonded lap joints by using ultrasonic guided (plate) waves. A noncontact, couplant-free method that employs capacitive air-coupled transducers is demonstrated for the inspection of thin aluminum joints with dimensions typical of aircraft fuselage and wing panels. Two types of bond defects, disbonded regions and regions of poorly cured (low-cohesive-strength) adhesive, are successfully detected by measuring the amplitude decrease of selected plate waves leaking from one adherend to the other one through the bondline. It is shown that proper choice of the vibrating mode structure, in terms of cross-sectional displacem…