scholarly journals Manufacture of Defined Residual Stress Distributions in the Friction-Spinning Process: Investigations and Run-to-Run Predictive Control

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 158
Author(s):  
Frederik Dahms ◽  
Werner Homberg
Keyword(s):  
Residual Stress ◽  
Predictive Control ◽  
Stress Generation ◽  
Hole Drilling ◽  
Stress Distributions ◽  
Forming Process ◽  
Hole Drilling Method ◽  
Drilling Method ◽  
Spinning Process ◽  
Flange Forming

Friction-spinning as an innovative incremental forming process enables high degrees of deformation in the field of tube and sheet metal forming due to self-induced heat generation in the forming area. The complex thermomechanical conditions generate non-uniform residual stress distributions. In order to specifically adjust these residual stress distributions, the influence of different process parameters on residual stress distributions in flanges formed by the friction-spinning of tubes is investigated using the design of experiments (DoE) method. The feed rate with an effect of −156 MPa/mm is the dominating control parameter for residual stress depth distribution in steel flange forming, whereas the rotation speed of the workpiece with an effect of 18 MPa/mm dominates the gradient of residual stress generation in the aluminium flange-forming process. A run-to-run predictive control system for the specific adjustment of residual stress distributions is proposed and validated. The predictive model provides an initial solution in the form of a parameter set, and the controlled feedback iteratively approaches the target value with new parameter sets recalculated on the basis of the deviation of the previous run. Residual stress measurements are carried out using the hole-drilling method and X-ray diffraction by the cosα-method.

Determination of Residual Stresses in Medium Density Fibreboard

Holzforschung ◽  
2000 ◽  
Vol 54 (2) ◽  
pp. 176-182 ◽  
Author(s):  
Jeroen van Houts ◽  
Debes Bhattacharyya ◽  
Krishnan Jayaraman
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Thickness Swell ◽  
Hole Drilling ◽  
Medium Density ◽  
Stress Distributions ◽  
Moisture Expansion ◽  
Hole Drilling Method ◽  
Drilling Method ◽  
Residual Internal Stress

Summary Due to the moisture and temperature gradients developed during hot pressing of medium density fibre-board (MDF), residual stresses occur within the board as it equilibrates to room conditions. It would be extremely useful to measure these residual stresses and to determine their effects on board properties such as moduli of elasticity and rupture in bending, internal bond strength and dimensional stability. In this article two methods, namely dissection and hole drilling, have been adapted to measure residual internal stress distributions in six different samples of industry produced MDF. The dissection method involves cutting several pieces of MDF perpendicular to the thickness direction at different depths. The residual stresses released by the dissection can be determined by measuring the curvatures of cut pieces and knowing their elastic moduli. The hole drilling method, on the other hand, involves mounting three strain gauges on the surface of a piece of MDF and drilling a hole to release residual stresses in close proximity. The released stresses are manifested as strains in the forms of which can be measured in three directions on the surface of the board. A theoretical model for predicting residual stresses involving various parameters has been developed and an excellent agreement with the experimental results from both the dissection and hole drilling methods has been achieved. Linear moisture expansion coefficient appears to have the greatest influence on residual stress. When compared against each other, the residual stresses measured by the hole drilling method show some shortcomings towards the centre of the board. While all six of the MDF boards exhibited similar trends in their residual stress distributions, significant differences were identified in the magnitudes of residual stress measured. Finally, some preliminary results linking the residual stress with the thickness swell of the samples and their surface densities have been presented.

The Influence of Chemical Composition on Residual Stresses in NiCoMo Alloy Deposits on 12 Ni Maraging Steel

2013 ◽  
Vol 768-769 ◽  
pp. 449-455 ◽  
Author(s):  
Zoran Bergant ◽  
Janez Grum
Keyword(s):  
Residual Stress ◽  
Chemical Composition ◽  
Residual Stresses ◽  
Base Material ◽  
Stress Generation ◽  
Hole Drilling ◽  
Residual Stress Field ◽  
Hole Drilling Method ◽  
Similar Chemical ◽  
Drilling Method

The in-plane residual stresses in laser cladded specimens, made of 12-nickel precipitation hardening maraging hot-working tool steel 1.2799 (SIST EN 10027-2) are analyzed using the hole drilling method. The CO2 laser was used to deposit the alloy NiCoMo-1 with significantly higher content of nickel and cobalt with austenitic microstructure at room temperature. The Nd:YAG laser was used to deposit the maraging alloy designated NiCoMo-2, with similar chemical composition as the base material. The comparison of residual stress field showed the sign and the magnitude of residual stresses depends on the chemical composition of the clad being deposited. The high tensile residual stresses were found in NiCoMo-1 layers and favorable compressive residual stresses were found in NiCoMo-2 layers. The metallurgical aspects of residual stress generation are discussed.

Development of Weld Residual Stress Measurement Method for Primed Steels

2017 ◽  
Author(s):  
Y. P. Yang ◽  
R. Dull ◽  
T. D. Huang ◽  
H. Rucker ◽  
M. Harbison ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Measurement ◽  
Hole Drilling ◽  
Stress Distributions ◽  
X Ray Diffraction ◽  
Ship Structures ◽  
X Ray ◽  
Hole Drilling Method ◽  
Weld Residual Stress ◽  
Drilling Method

Welding, as a major manufacturing process in shipbuilding, induces residual stress and distortion that affects buckling strength, fatigue performance, corrosion resistance, and dimensional stability of ship structures. Understanding residual stress in ship structures is required in engineering design to ensure structural strength and safety and is essential in dimensional accuracy for distortion control during fabrication. However, measuring residual stress in ship structures presents unique challenges, such as structure complexity, surface primer, and a non-friendly measurement environment. Fortunately, portable X-ray diffraction equipment has been successfully developed and proven accurate in other industries to measure residual stress. This study is to evaluate the feasibility of measuring residual stress in a shipyard environment in terms of accuracy and adaptability. Typical welded joints (butt joint and T-joint) were selected for evaluation instead of evaluating complicated ship structures. The welded joints were fabricated using common shipyard welding procedures. This makes the evaluation easier since weld residual stress distributions and magnitudes on these joints are well understood. In addition, the hole-drilling method was also used to validate the X-ray diffraction results. Measured results show that X-ray diffraction can penetrate the pre-construction surface primer used in shipbuilding to directly measure residual stress of the metal surface, without the need to remove the surface primer. The residual stress data measured by X-ray diffraction agreed with the data obtained by the hole-drilling method. In addition, the residual stress trend measured by X-ray diffraction agreed with the theoretical residual-stress distributions. This study concluded that a portable X-ray diffraction is a potential technology for residual stress measurement in a shipyard.

Residual Stress Measurements in an Autofrettage Tube Using Hole Drilling Method

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Hamid Jahed ◽  
Mohammad Reza Faritus ◽  
Zeinab Jahed
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Hoop Stress ◽  
Test Method ◽  
Test Material ◽  
Hole Drilling ◽  
Hole Drilling Method ◽  
Ring Sample ◽  
Drilling Method ◽  
American Society

Relieved strains due to drilling hole in a ring sample cut from an autofrettage cylinder are measured. Measured strains are then transformed to residual stresses using calibration constants and mathematical relations of elasticity based on ASTM standard recommendations (American Society for Testing and Materials, ASTM E 837-08, 2008, “Standard Test Method for Determining Residual Stresses by the Hole-Drilling Strain-Gage Method,” American Society for Testing and Materials). The hydraulic autofrettage is pressurizing a closed-end long cylinder beyond its elastic limits and subsequently removing the pressure. In contrast to three-dimensional stress state in the autofrettage tube, the stress measurement in hole drilling method is performed on a traction free surface formed from cutting the ring sample. The process of cutting the ring sample from a long autofrettaged tube is simulated using finite element method (FEM) and the redistribution of the residual stress due to the cut is discussed. Hence, transformation of the hole drilling measurements on the ring slice to the autofrettage residual stresses is revealed. The residual stresses are also predicted by variable material properties (VMP) method (Jahed, H., and Dubey, R. N., 1997, “An Axisymmetric Method of Elastic-Plastic Analysis Capable of Predicting Residual Stress Field,” Trans. ASME J. Pressure Vessel Technol., 119, pp. 264–273) using real loading and unloading behavior of the test material. Prediction results for residual hoop stress agree very well with the measurements. However, radial stress predictions are less than measured values particularly in the middle of the ring. To remove the discrepancy in radial residual stresses, the measured residual hoop stress that shows a self-balanced distribution was taken as the basis for calculating residual radial stresses using field equations of elasticity. The obtained residual stresses were improved a lot and were in good agreement with the VMP solution.

scholarly journals Incremental Hole-Drilling Method Vs. Thin Components: A Simple Correction Approach

2014 ◽  
Vol 996 ◽  
pp. 283-288 ◽  
Author(s):  
Esther Held ◽  
Simone Schuster ◽  
Jens Gibmeier
Keyword(s):  
Residual Stress ◽  
Thin Metal ◽  
Hole Drilling ◽  
Depth Profiles ◽  
Hole Drilling Method ◽  
Incremental Hole Drilling ◽  
Metal Sheets ◽  
Drilling Method ◽  
Measured Strain ◽  
The Impact

The incremental hole-drilling method is a widely used technique to determine residual stress depth profiles in technical components. Its application is limited in respect to the components geometry, for instance the components thickness. In this paper, a direct correction of the measured strain relaxations is proposed to consider the impact of deviant geometries, here the component thickness, on the residual stress evaluation that moreover, allows the application of commercially available evaluation software. The herein proposed approach is based on finite element simulation of the incremental hole drilling. The simulated strain relaxations for thin metal sheets are evaluated with an algorithm as used in commercially available evaluation software (i) for uncorrected data as well as (ii) for strain data corrected by the proposed correction procedure. It is shown that the correction approach leads to a significant improvement of the measurement accuracy. Further, by means of the approach residual stress depth profiles in thin metal sheets can be as usual determined using commercial evaluation software for the incremental hole-drilling method regardless of the algorithm used, i.e. differential or integral.

scholarly journals Achievements in Micromagnetic Techniques of Steel Plastic Stage Evaluation

2020 ◽  
Vol 20 (1) ◽  
pp. 16-55 ◽  
Author(s):  
M. F. de Campos
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
Elastic Deformation ◽  
Magnetic Measurements ◽  
Soft Magnetic Materials ◽  
Hysteresis Curve ◽  
Hole Drilling ◽  
Hole Drilling Method ◽  
Drilling Method ◽  
The Difference

AbstractThe investigation of plastic deformation and residual stress by non-destructive methods is a subject of large relevance for the industry. In this article, the difference between plastic and elastic deformation is discussed, as well as their effects on magnetic measurements, as hysteresis curve and Magnetic Barkhausen Noise. The residual stress data can be obtained with magnetic measurements and also by the hole drilling method and x-ray diffraction measurements. The residual stress level obtained by these three different methods is different, because these three techniques evaluate the sample in different depths. Effects of crystallographic texture on residual stress are also discussed. The magnetoelastic term should be included in micromagnetic methods for residual stress evaluation. It is discussed how the micromagnetic energy Hamiltonian should be expressed in order to evaluate elastic deformation. Plastic deformation can be accounted in micromagnetic models as a term that increases the coercive field in soft magnetic materials as the steels are.

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