FAILURE OF CFRP AND TITANIUM TUBULAR ADHESIVE LAP JOINTS AT EXTREME TEMPERATURES

2021 ◽  
Author(s):  
ISAIAH KAISER ◽  
CHAO ZHANG ◽  
K. T. TAN
Keyword(s):  
Elevated Temperatures ◽  
Mechanical Performance ◽  
Extreme Temperature ◽  
Statistical Design ◽  
Lap Joints ◽  
Shear Stresses ◽  
Micro Computed Tomography ◽  
Element Analysis ◽  
Composite Damage ◽  
Interlaminar Shear

In this work, carbon fiber reinforced polymer and titanium adhesive tubular lap- joints (TLJs) at cold-temperature, room-temperature, and elevated-temperature are studied. Finite element analysis is employed to investigate the competing damage mechanisms within the TLJs. The relationship between the joint strength and adhesive bondline length is also determined. X-ray micro-computed tomography (μCT) technique is utilized to analyze composite damage characteristics; whilst statistical design of experiment (DoE) approach is used to understand the interaction between bondline length and temperature on the mechanical performance of TLJs. Results show a mixed-mode failure region at elevated-temperatures, causing the TLJ to fail by either interlaminar shear or titanium net-section fracture. Results further reveal that deformation within the titanium creates shear stresses on the composite tube, leading to the initiation, propagation, and coalescence of delamination. Employing numerical, experimental, and statistical techniques, this works provides insights into the parameters and mechanisms affecting the behavior and failure of adhesive TLJs at extreme temperature conditions.

Failure analysis of simple overlap bonding joints and numerical investigation of the adhered tip geometry effect on the joint strength

2021 ◽  
Vol 63 (11) ◽  
pp. 1007-1011
Author(s):  
İsmail Saraç
Keyword(s):  
Finite Element Analysis ◽  
Experimental Study ◽  
Finite Element ◽  
Reference Model ◽  
Lap Joints ◽  
Shear Stresses ◽  
Element Analysis ◽  
Single Lap Joints ◽  
Failure Loads ◽  
Previous Experimental Study

Abstract This study was carried out in two stages. In the first step, a numerical study was performed to verify the previous experimental study. In accordance with the previous experimental study data, single lap joints models were created using the ANSYS finite element analysis program. Then, nonlinear stress and failure analyses were performed by applying the failure loads obtained in the experimental study. The maximum stress theory was used to find finite element failure loads of the single lap joints models. As a result of the finite element analysis, an approximate 80 % agreement was found between experimental and numerical results. In the second step of the study, in order to increase the bond strength, different overlap end geometry models were produced and peel and shear stresses in the adhesive layer were compared according to the reference model. As a result of the analyses, significant strength increases were calculated according to the reference model. The strength increase in model 3 and model 5 was found to be 80 % and 67 %, respectively, relative to the reference model.

Flexure–shear interaction in hybrid steel I-girders at ambient and elevated temperatures

2018 ◽  
Vol 22 (6) ◽  
pp. 1501-1516 ◽  
Author(s):  
Abbas Ghadami ◽  
Vahid Broujerdian
Keyword(s):  
Elevated Temperatures ◽  
Steel Plate ◽  
Theoretical Research ◽  
Shear Stresses ◽  
Element Analysis ◽  
Interaction Behavior ◽  
The Finite Element Analysis ◽  
Shear Buckling ◽  
The Moment ◽  
Good Agreement

In literature, there is no theoretical research focusing on moment–shear interaction behavior of the hybrid girders. This article investigates the moment–shear interaction behavior of non-composite hybrid steel plate I-girders at ambient and elevated temperatures. In this regard, based on a more realistic distribution of bending and shear stresses, theoretical equations have been proposed to achieve the moment–shear interaction curve without considering shear buckling. The results obtained from the proposed equations were compared with the results of the existing experimental data and those of the finite element analysis. According to the results, there is good agreement between them.

Study on Thermal Stresses the Extreme Temperature in Bridge Deck Pavements Using FEM Analysis

2012 ◽  
Vol 482-484 ◽  
pp. 1718-1721
Author(s):  
Hai Bin Li ◽  
Yan Ping Sheng ◽  
Qian Wang
Keyword(s):  
Finite Element ◽  
Elastic Modulus ◽  
Thermal Stresses ◽  
Bridge Deck ◽  
Extreme Temperature ◽  
Fem Analysis ◽  
Maximum Principal Stress ◽  
Shear Stresses ◽  
Element Analysis ◽  
Wide Range

The thermal stresses at the extreme temperatures in bridge deck pavements (BDP) was analyzed in the paper. The sample bridge deck and asphalt concrete pavements were analyzed. The maximum principal and shear stresses in the BDP at the wide range of temperatures were calculated using 3D finite element method. The compared results showed a strong linear correlation between the BDP maximum principal stress and the elastic modulus. This linear relationship also existed between the shear stress and the elastic modulus. From the finite element analysis, it is found that the BDP elastic modulus affects the thermal stress more than the thickness of BDP. With the consideration of thermal stresses of BDP, the thickness of BDP from 6 to 12 cm is recommended for the BDP construction.

scholarly journals Femoral mechanical performance of precocial and altricial birds: a simulation study

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xinsen Wei ◽  
Zihui Zhang
Keyword(s):  
Mechanical Performance ◽  
Axial Loading ◽  
Columba Livia ◽  
Ontogenetic Changes ◽  
Micro Computed Tomography ◽  
Erect Posture ◽  
Element Analysis ◽  
Lower Strain ◽  
Altricial Birds ◽  
Radial Loading

AbstractBackgroundAs the major load-bearing structures, bones exhibit various properties related to mechanical performance to adapt to different locomotor intensities. The habits and ontogenetic changes of locomotion in animals can, thus, be explored by assessing skeletal mechanical performance.MethodsIn this study, we investigated the growing femoral mechanical performance in an ontogenetic series of Cabot’s Tragopans (Tragopan caboti) and Pigeons (Columba livia domestica). Micro-computed tomography-based finite element analysis was conducted to evaluate the stress, strain, and strain energy density (SED) of femora under axial and radial loading.ResultsFemora deflected medio-laterally and dorso-ventrally under axial and radial loading, respectively. Femora deformed and tensed more severely under radial loading than axial loading. In adult individuals, Cabot’s Tragopans had lower strain and SED than pigeons. During ontogeny, the strain and SED of pigeons decreased sharply, while Cabot’s Tragopans showed moderately change. The structural properties of hatchling pigeons are more robust than those of hatchling Cabot’s Tragopans.ConclusionsLimb postures have dominant effect on skeletal deformation. The erect posture is preferred by large mammals and birds to achieve a high safety factor of bones during locomotion. Adult Cabot’s Tragopans have stronger femora than pigeons, reflecting a better bone adaption to the terrestrial locomotion of the studied pheasant species. Changes in strain and SED during growth reflect the marked difference in locomotor ability between precocial and altricial hatchlings. The femora of hatchling Cabot’s Tragopans were built with better energy efficiency than deformation resistance, enabling optimized mechanical performance. In contrast, although weak in mechanical function at the time of hatching, pigeon femora were suggested to be established with a more mature structural design as a prerequisite for rapid growth. These results will be helpful for studies regarding developmental patterns of fossil avian species.

scholarly journals THE PROJECTED EFFECT FROM ACCEPTANCE OF CONSTRUCTIVE SOLUTIONS TO ENSURE THE RELIABILITY OF AN INDUSTRIAL FACILITY

Vestnik MGSU ◽  
2015 ◽  
pp. 80-89
Author(s):  
Robert Alekseevich Turusov ◽  
Hamed Memarianfard
Keyword(s):  
Three Dimensional ◽  
Outer Radius ◽  
Shear Stresses ◽  
Element Analysis ◽  
Thermal Residual Stresses ◽  
Filament Wound ◽  
Inner Radius ◽  
Dimensional Finite Element ◽  
Interlaminar Shear ◽  
Three Dimensional Finite Element

In this paper a three-dimensional finite element analysis employed to predict thermal residual stresses field which arises during the cooling stage at the free edges of a thick walled filament wound cylinder with cross-ply lamination. The inner radius of composite is 50 mm and outer radius is 75 mm and the thickness of steel mandrel is 3 mm. The results showed that the radial stresses near the free ends of the cylinder increased two times compared to radial stresses in the middle of the cylinder and interlaminar shear stresses exceeded 6 MPa close to the free edges.Thus, a two-dimensional stress analysis does not fully reflect the complex state of stress of thick-walled cross-ply filament wound cylinders.

Finite Element Analysis of Tire/Rim Interface Forces Under Braking and Cornering Loads

1992 ◽  
Vol 20 (2) ◽  
pp. 83-105 ◽  
Author(s):  
J. P. Jeusette ◽  
M. Theves
Keyword(s):  
Finite Element ◽  
Shear Stress ◽  
Contact Pressure ◽  
Element Model ◽  
Shear Stresses ◽  
Detailed Knowledge ◽  
Stress Distributions ◽  
Element Analysis ◽  
Plane Shear ◽  
Normal Contact

Abstract During vehicle braking and cornering, the tire's footprint region may see high normal contact pressures and in-plane shear stresses. The corresponding resultant forces and moments are transferred to the wheel. The optimal design of the tire bead area and the wheel requires a detailed knowledge of the contact pressure and shear stress distributions at the tire/rim interface. In this study, the forces and moments obtained from the simulation of a vehicle in stationary braking/cornering conditions are applied to a quasi-static braking/cornering tire finite element model. Detailed contact pressure and shear stress distributions at the tire/rim interface are computed for heavy braking and cornering maneuvers.

scholarly journals Effect of Micro Solidification Crack on Mechanical Performance of Remote Laser Welded AA6063 Fillet Lap Joint in Automotive Battery Tray Construction

2021 ◽  
Vol 11 (10) ◽  
pp. 4522
Author(s):  
Tianzhu Sun ◽  
Pasquale Franciosa ◽  
Conghui Liu ◽  
Fabio Pierro ◽  
Darek Ceglarek
Keyword(s):  
Laser Welding ◽  
Fusion Zone ◽  
Aluminium Alloys ◽  
Mechanical Performance ◽  
Lap Joints ◽  
Fatigue Durability ◽  
Micro Cracks ◽  
Remote Laser Welding ◽  
Weld Fatigue ◽  
Weld Root

Remote laser welding (RLW) has shown a number of benefits of joining 6xxx aluminium alloys such as high processing speed and process flexibility. However, the crack susceptibility of 6xxx aluminium alloys during RLW process is still an open problem. This paper experimentally assesses the impact of transverse micro cracks on joint strength and fatigue durability in remote laser welding of AA6063-T6 fillet lap joints. Distribution and morphology of transverse micro cracks were acquired by scanning electron microscope (SEM) on cross-sections. Grain morphology in the weld zone was determined by electron backscatter diffraction (EBSD) while static tensile and dynamic fatigue tests were carried out to evaluate weld mechanical performance. Results revealed that increasing welding speed from 2 m/min to 6 m/min did not introduce additional transverse micro cracks. Additionally, welding at 2 m/min resulted in tensile strength improvement by 30% compared to 6 m/min due to the expansion of fusion zone, measured by the throat thickness, and refinement of columnar grains near fusion lines. Furthermore, the weld fatigue durability is significantly higher when fracture occurs in weld root instead of fusion zone. This can be achieved by increasing weld root angle with optimum weld fatigue durability at around 55°.

Mechanical performance and failure criterion of coral concrete under combined compression-shear stresses

2021 ◽  
Vol 288 ◽  
pp. 123050
Author(s):  
Bing Liu ◽  
Jingkai Zhou ◽  
Xiaoyan Wen ◽  
Jianhua Guo ◽  
Zhiheng Deng ◽  
...  
Keyword(s):  
Failure Criterion ◽  
Mechanical Performance ◽  
Shear Stresses

scholarly journals Design and Characterization of Microscale Auxetic and Anisotropic Structures Fabricated by Multiphoton Lithography

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 446
Author(s):  
Ioannis Spanos ◽  
Zacharias Vangelatos ◽  
Costas Grigoropoulos ◽  
Maria Farsari
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Mechanical Performance ◽  
Element Analysis ◽  
Mechanical Responses ◽  
Multiphoton Lithography ◽  
Anisotropic Structures ◽  
Scanning Electron

The need for control of the elastic properties of architected materials has been accentuated due to the advances in modelling and characterization. Among the plethora of unconventional mechanical responses, controlled anisotropy and auxeticity have been promulgated as a new avenue in bioengineering applications. This paper aims to delineate the mechanical performance of characteristic auxetic and anisotropic designs fabricated by multiphoton lithography. Through finite element analysis the distinct responses of representative topologies are conveyed. In addition, nanoindentation experiments observed in-situ through scanning electron microscopy enable the validation of the modeling and the observation of the anisotropic or auxetic phenomena. Our results herald how these categories of architected materials can be investigated at the microscale.

scholarly journals Behavior of Offshore Pile in Calcareous Sand—Case Study

2021 ◽  
Vol 9 (8) ◽  
pp. 839
Author(s):  
Tarek N. Salem ◽  
Nadia M. Elkhawas ◽  
Ahmed M. Elnady
Keyword(s):  
Load Capacity ◽  
High Stress ◽  
Embedment Depth ◽  
Shear Stresses ◽  
Northern Coast ◽  
Compression Tests ◽  
Calcareous Sand ◽  
Element Analysis ◽  
Mixing Ratios

The erosion of limestone and calcarenite ridges that existed parallel to the Mediterranean shoreline forms the calcareous sand (CS) formation at the surface layer of Egypt's northern coast. The CS is often combined with broken shells which are considered geotechnically problematic due to their possible crushability and relatively high compressibility. In this research, CS samples collected from a site along the northern coast of Egypt are studied to better understand its behavior under normal and shear stresses. Reconstituted CS specimens with different ratios of broken shells (BS) are also investigated to study the effect of BS ratios on the soil mixture strength behavior. The strength is evaluated using laboratory direct-shear and one-dimensional compression tests (oedometer test). The CS specimens are not exposed to significant crushability even under relatively high-stress levels. In addition, a 3D finite element analysis (FEA) is presented in this paper to study the degradation offshore pile capacity in CS having different percentages of BS. The stress–strain results using oedometer tests are compared with a numerical model, and it gave identical matching for most cases. The effects of pile diameter and embedment depth parameters are then studied for the case study on the northern coast. Three different mixing ratios of CS and BS have been used, CS + 10% BS, CS + 30% BS, and CS + 50% BS, which resulted in a decrease of the ultimate vertical compression pile load capacity by 8.8%, 15%, and 16%, respectively.

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