Analysis of a flexural wave due to a laser heating pulse: The two-layer assembly case

2002 ◽  
Vol 216 (12) ◽  
pp. 1165-1174 ◽  
Author(s):  
B S Yilbas ◽  
S J Hyder
Keyword(s):  
Layer Thickness ◽  
Steel Plate ◽  
Equivalent Stress ◽  
Inconel 625 ◽  
Flexural Wave ◽  
Pressure Force ◽  
Temporal Behaviour ◽  
Fixed End ◽  
Oxygen Fuel ◽  
Layer Assembly

In the present study laser ablation of a two-layer assembly with a cantilever arrangement is considered. The recoil pressure generated at the vapour front-workpiece interface is formulated and the resulting pressure force (loading force) is computed. The flexural motion of the workpiece due to the loading force is formulated. The first layer of the workpiece is Inconel 625 with a thickness on the order of 200 μm, which may resemble the HVOF (high-velocity oxygen fuel) coating, while the second layer is 1 mm thick stainless steel plate. The simulations are repeated for four values of the first layer thickness and the relation between the magnitude of the displacement and the first layer thickness is discussed. It is found that the displacement of the workpiece reaches as high as 2 μm in the region close to the free end, while the equivalent stress level is high in the region close to the fixed end. The temporal behaviour of the equivalent stress almost follows the displacement behaviour of the workpiece. As the first layer thickness increases, the displacement reduces. The variation of displacement with the first layer thickness is almost linear and the slope of this variation attains high values for certain time periods in the flexural motion.

Transverse Modes and Frequencies of Beams Translating between Fixed end Supports

1973 ◽  
Vol 15 (3) ◽  
pp. 159-164 ◽  
Author(s):  
A. Simpson
Keyword(s):  
Equations Of Motion ◽  
Translational Motion ◽  
Axial Loading ◽  
Mode Shapes ◽  
Flexural Wave ◽  
Transverse Modes ◽  
Translation Velocity ◽  
Flexural Wave Propagation ◽  
Point To Point ◽  
Fixed End

The effects of longitudinal steady translational motion on the vibration frequencies and modes of simple Euler beams are outlined. An example shows that the natural frequencies decrease monotonically with increasing translation velocity, while the mode shapes are complex, indicating significant phase disparities from point to point across the span. Divergence is shown to occur when the translation velocity is greater than the fundamental flexural wave propagation velocity. More general equations of motion, governing the translating Timoshenko beam under axial loading, are derived in Appendix 1.

Influence of layers on flexural motion of a multilayer assembly due to the laser ablation process

2003 ◽  
Vol 217 (8) ◽  
pp. 945-954 ◽  
Author(s):  
B S Yilbas ◽  
J Hyder
Keyword(s):  
Equivalent Stress ◽  
Substrate Material ◽  
Liquid Interface ◽  
Flexural Wave ◽  
Maximum Magnitude ◽  
Pressure Loading ◽  
Maximum Displacement ◽  
Recoil Pressure ◽  
Laser Ablation Process ◽  
Maximum Equivalent Stress

Laser-induced evaporation results in recoil pressure at the vapour-liquid interface, which in turn gives rise to flexural wave generation in the substrate material due to impact pressure loading at the interface. In the present study, recoil pressure due to laser non-conduction limited heating is formulated and because of pressure loading at the vapour-liquid interface the flexural motion of the substrate material is modelled. A multilayer cantilever arrangement of the workpiece, consisting of layers of steel and Inconel alloy, is considered. In order to investigate the influence of the number of layers on the resulting flexural motion and stress fields, four cases and three layer arrangements are taken into account. It is found that the maximum displacement in the order of 10-4m occurs while the maximum equivalent stress is about 20 MPa. The maximum magnitude of shear stress is higher than that of equivalent stress.

scholarly journals On the Hot Isostatic Pressing of Inconel 625 Structures built using Laser Powder Bed Fusion at Higher Layer Thickness

2021 ◽  
Author(s):  
Saurav Kumar Nayak ◽  
Arackal Narayanan Jinoop ◽  
Christ Prakash Paul ◽  
Vesangi Anil Kumar ◽  
Dineshraj Subburaj ◽  
...  
Keyword(s):  
Layer Thickness ◽  
Volume Fraction ◽  
Hot Isostatic Pressing ◽  
Microstructural Analysis ◽  
Inconel 625 ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
Isostatic Pressing ◽  
Elemental Segregation

Abstract This paper reports the effect of Hot Isostatic Pressing (HIPing) on the porosity, microstructure and mechanical properties of Laser Powder Bed Fusion (LPBF) IN625 structures built at a higher layer thickness of 100 µm. It is observed that the process-induced pores/voids of volume fraction (Vf) 0.43% in as-built IN625 structures are reduced significantly to ~ 0.01% after HIPing treatment. The microstructure is changed from fine columnar dendrites to coarse equiaxed dendrites. The microstructural analysis of as-built structures reveals the presence of cellular/ dendritic growth along with elemental segregation of Nb, Si and C and precipitation of Nb-rich carbides. Whereas, coarse recrystallized microstructure along with elemental segregation of Si and precipitation of Nb, Mo and Cr rich carbides are observed in Hot Isostatic Pressed (HIPed) samples. HIPed structures exhibit lower tensile s trength, higher ductility, and lower anisotropy as compared to LPBF built structures. There is a reduction in the Vickers micro-hardness of IN625 samples after HIPing and the values are observed to be similar to their conventional counterparts. Further, an increase in the energy storage capacity of the material is observed after HIPing treatment through Automated Ball Indentation (ABI®) studies. The study paves a way to develop ~100% dense, defect-free and isotropic engineering components using LPBF.

Buckling Analysis of Belly Shaped Composite Column

2018 ◽  
Vol 7 (3.12) ◽  
pp. 715
Author(s):  
S Kesavan ◽  
S Ramesh ◽  
Alexabhishek . ◽  
J S.Sudarsan ◽  
P Vanamoorthy kumaran ◽  
...  
Keyword(s):  
Slenderness Ratio ◽  
Equivalent Stress ◽  
Buckling Load ◽  
Composite Column ◽  
Compression Load ◽  
End Conditions ◽  
The Mean ◽  
Fixed End ◽  
Effective Use ◽  
Strength Constraints

The study of Non prismatic column is designed to minimize the volume of material in the column by changing its shape, the column is subject to both buckling and strength constraints under axial compression load. The belly column is designed as Encased Composite column to improve the strength and ductility of column. The effective use of material through optimal shape of the column. Five models have been created in ANSYS WORKBENCH and all the columns having the same volume of materials, fixed end conditions and length of column. The behaviour of non-prismatic column is always based on tapering ratio and the slenderness ratio of the column. As the taper ratio increases, the elastic buckling load increases and stress decreases in the mean while the maximum stress occurs in the prismatic column compared with the non-prismatic column. As a result of this analysis Equivalent stress, Equivalent elastic strain, Total Deformation and Buckling load Deformation was observed and hence Stress-Strain graphs, Load -Deformation graphs and Mode-Load multiplier graph had been plotted.  

scholarly journals FEATURES OF CALCULATING THE DEFLECTION OF ROUND PLATES

2021 ◽  
Vol 1 (1) ◽  
pp. 211-212
Author(s):  
Anatoliy Cherepanov
Keyword(s):  
Steel Plate ◽  
Pressure Force ◽  
Stress Coefficient ◽  
Flat Steel ◽  
Plate Deflection

A method for calculating the deflection of a round flat steel plate bearing an ax isymmetric load is considered. For practical calculations, dimensionless coefficients of deflection in the center of the plate, deflection at a certain distance from the center of the plate, the stress coefficient and the accompanying function, which depends on the deflection of the plate and the pressure force on it, are used.

Laminar Vortex Shedding in the Wake of a Cube

2020 ◽  
Author(s):  
Majid Hassan Khan ◽  
Hamid H Khan ◽  
Atul Sharma ◽  
Amit Agrawal
Keyword(s):  
Vortex Shedding ◽  
Three Dimensional ◽  
Axial Direction ◽  
Separation Distance ◽  
Pressure Force ◽  
Hairpin Vortices ◽  
Temporal Behaviour ◽  
Normal Orientation ◽  
Constant Shape ◽  
First Time

Abstract Flow around a cube is numerically studied in the laminar vortex shedding regime at Re = 276. The objective is to examine the three dimensional vortex shedding mechanism and understand the temporal behaviour of the wake. Hairpin vortices were identified using λ2 criterion. The wake of the cube sheds paired hairpin vortices which moves in the streamwise direction and attains a constant shape with time. The analysis of separation distance and angular orientation of hairpin vortices for flow around a cube are presented here for the first time in the literature. The separation (d) between the paired hairpin vortices scales as t−1/2. The orientation of hairpin vortices change with time and attain a near-normal orientation with respect to the axial direction. A quasi-periodic nature of the flow has been revealed by the phase plots. The drag and side forces generated due to the flow are studied with pressure force mostly contributing to the drag. One of the side force coefficients dominates owing to the asymmetry of the wake in one plane and symmetry in the other orthogonal streamwise plane. These results clearly bring out the asymmetric nature of flow in the shedding regime.

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