Influence of the Bolt Material Properties on the Ultimate Capacity of End Plate Bolted Joint Subjected to Column Loss

2021 ◽  
Vol 885 ◽  
pp. 133-139
Author(s):  
Roberto Tartaglia ◽  
Alessia Campiche
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Material Properties ◽  
Finite Element Simulations ◽  
Material Strength ◽  
Bolted Joint ◽  
Ultimate Capacity ◽  
Catenary Action ◽  
Beneficial Effects ◽  
End Plate

This paper investigates the performance of extended stiffened end-plate bolted beam-to-column joints subjected a column loss scenario by means of finite element simulations. An advanced numerical model was developed, and its effectiveness was validated against the experimental results. The influence of the bolt strengthening on the column loss action was investigated changing the grade of bolts. The results showed that the joint performance under column loss scenario are deeply related to the development of the catenary action that depends from the connection ductility; therefore increasing the bolt material strength will provide beneficial effects on the joint capacity under the column loss.

Analysis of Chip Damage Risk in Thermosonic Wire Bonding

2011 ◽  
Vol 478 ◽  
pp. 75-80 ◽  
Author(s):  
Christian Dresbach ◽  
Georg Lorenz ◽  
Matthias Petzold ◽  
Holm Altenbach
Keyword(s):  
Finite Element ◽  
Material Properties ◽  
Electron Backscatter Diffraction ◽  
Copper Wire ◽  
Diffraction Method ◽  
Dielectric Materials ◽  
Finite Element Simulations ◽  
Flat Punch ◽  
Extreme Change ◽  
Damage Risk

In current highly integrated microelectronic devices including system-in-package and stacked-die solutions, system reliability is strongly influenced by reliability of the gold and copper wire bond interconnections. Especially in state-of-the-art ICs containing mechanically sensitive low-K dielectric materials, controlling the mechanical properties of the free air ball (FAB) is of utmost significance due to chip damage risks during the bond process. Because of an extreme change in microstructure when forming the FAB, the material properties change significantly. Consequently, it is necessary to determine the properties of the FAB itself, when analyzing chip damage risks via finite element simulations. We present a micro-compression test that allows the determination of the hardening behavior of typical gold and copper FABs with diameters between 45 µm and 75 µm. In this test a FAB is placed on a diamond support or a test capillary and loaded by a diamond flat punch in a microindenter. The hardening was determined from force/displacement behavior via parameter identification using finite element simulations. The identified yield stresses correlate very well with the microstructure which was determined by electron backscatter diffraction method; this means that the yield stress decreases with increasing mean grain diameter in analogy to the Hall-Petch correlation. Compared to unprocessed wires the initial yield stresses are 50% to 60% lower. Considering these material properties, the damage risk during bonding on complex bond pad layouts can be predicted more realistically. This can be shown by results of real bond structures.

scholarly journals Analytic analysis of auxetic metamaterials through analogy with rigid link systems

2018 ◽  
Vol 474 (2210) ◽  
pp. 20170753 ◽  
Author(s):  
Daniel Rayneau-Kirkhope ◽  
Chengzhao Zhang ◽  
Louis Theran ◽  
Marcelo A. Dias
Keyword(s):  
Finite Element ◽  
Mechanical Behaviour ◽  
Material Properties ◽  
Threshold Value ◽  
Finite Element Simulations ◽  
Elastic Instability ◽  
Lattice Systems ◽  
Rigid Link ◽  
Post Buckling ◽  
Insight Into

In recent years, many structural motifs have been designed with the aim of creating auxetic metamaterials. One area of particular interest in this subject is the creation of auxetic material properties through elastic instability. Such metamaterials switch from conventional behaviour to an auxetic response for loads greater than some threshold value. This paper develops a novel methodology in the analysis of auxetic metamaterials which exhibit elastic instability through analogy with rigid link lattice systems. The results of our analytic approach are confirmed by finite-element simulations for both the onset of elastic instability and post-buckling behaviour including Poisson’s ratio. The method gives insight into the relationships between mechanisms within lattices and their mechanical behaviour; as such, it has the potential to allow existing knowledge of rigid link lattices with auxetic paths to be used in the design of future buckling-induced auxetic metamaterials.

scholarly journals Effect of Axial Preload on Double-Lap Bolted Joints: Numerical Study

2012 ◽  
Author(s):  
Taha Benhaddou ◽  
Pierre Stephan ◽  
Alain Daidie ◽  
Clément Chirol ◽  
Jean-Baptiste Tuery
Keyword(s):  
Fatigue Life ◽  
Numerical Model ◽  
Numerical Study ◽  
Plate Thickness ◽  
Fatigue Tests ◽  
Fracture Load ◽  
Bolted Joint ◽  
Initial State ◽  
Beneficial Effects ◽  
Bending Stresses

This paper presents the numerical study of double-lap bolted joint behavior. This type of joint is mainly used in aeronautical structures to transfer the given loads (by both adhesion and by deformation-shearing). Recent articles, based on experimental fatigue tests conducted by AIRBUS, have shown the beneficial effects of preloading on the fatigue life of these joints. Finite element analyses were performed using ABAQUS® to study the behavior of a double-lap single-bolted joint with different plate thicknesses (joint thickness = 0.5d, 1d, 1.5d, 2d 2.5d, 3d, 3.5d and 4d, where d is the bolt diameter). The numerical model provides several important results. In the case of static loads, elasto-plastic constitutive laws of the bolt and the plate materials allowed the process to be simulated on the basis of tension tests. Mechanical aspects of this type of assembly are numerically identified; from the initial state of adhesion to the state of plastic deformation of parts in contact including the stage of generalized slippage. We note that the fracture load increases slightly when the bolted joint is preloaded while the failure area remains the same. In the case of large plate thickness, the connection is subjected to significant bending stresses and this involves strong local plasticization associated with the loss of preload. In the case of cyclic loading, we consider a numerical model based on the simulation of one loading/unloading cycle. A noticeable decrease in initial preload is observed for certain configurations, in particular those with the largest plate thickness. This phenomenon is related to the effect of strain hardening of the bolt during the first loading cycles. Some experimental work by AIRBUS has shown that the fatigue life of assemblies is dependent on the material plate thicknesses. An extension to the case of a multiple-bolted joint (three rows of three bolts) is finally discussed and highlights the evolution of the rate of load transmission with respect to the applied load.

scholarly journals Finite Element Simulations on the Tensile Resistance of Bolted End-Plate Connections with Tubular Members

2018 ◽  
Vol 12 (1) ◽  
pp. 177-186 ◽  
Author(s):  
Maël Couchaux ◽  
Mario D’Aniello ◽  
Lucia Falciano ◽  
Beatrice Faggiano ◽  
Mohammed Hjiaj ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Simulations ◽  
Effective Length ◽  
Finite Element Analyses ◽  
Hollow Section ◽  
End Plate ◽  
General Rules ◽  
Proper Definition ◽  
Plate Connections ◽  
Definition Of

Background: Bolted end-plate connections represent the simplest and cheapest way to connect tubular members. EN1993:1-8 provides the general rules based on component method. However, in the case of splices with tubular members the proper definition of the effective length around corner bolts is not clearly addressed. Objective: The objective of the study is to investigate the accuracy and the effectiveness of the existing analytical predictions to estimate the tensile resistance of end-plate connections with tubular members where corner bolts are adopted. Method: Parametric finite element analyses were carried out to investigate the tensile strength of connections of both square and rectangular hollow sections. Results: The tension resistance is largely influenced by the corner bolts. Indeed, the connections with corner bolts exhibit larger resistance that increases when the bolts are closer to the corner of the tubular member. However, reducing the distance between the bolt and the wall of the tubular section can affect the splice ductility. Conclusion: • The method proposed Steige and Weynand to calculate the tension resistance of connections with bolts distributed on all sides of the splice is consistent with EN 1993-1-8. • The finite element simulations showed that the corner bolts can increase the resistance of the connection. In addition, the bolt layout can be optimised by placing the bolts as close to the hollow section as possible.

Residual Strength of Tubular Columns With Localized Thickness Loss

2021 ◽  
Author(s):  
Mostafa Atteya ◽  
Ove Mikkelsen ◽  
Narve Oma ◽  
Gerhard Ersdal
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Experimental Work ◽  
Nonlinear Finite Element ◽  
Ultimate Capacity ◽  
Axial Loads ◽  
Element Analysis ◽  
Tubular Columns ◽  
Nonlinear Finite Element Methods ◽  
Good Agreement

Abstract This paper provides a comprehensive finite element analysis to investigate the ultimate capacity of corroded members under concentric axial loads. The paper investigates previous experimental work on stocky and slender tubular columns with simulated patch corrosion and provides a numerical model that can estimate the columns capacities. Further, a parametric study is performed to investigate the effect of geometric parameters such as location, height, and width of corrosion patch on the ultimate capacity of corroded columns. Finally, the paper presents a comparison between laboratory tests to the formulae of superseded standards and numerical analysis using nonlinear finite element methods. The numerical model proposed in this paper show good agreement with the results from the experimental work.

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