scholarly journals Simulation and automation of aluminium panel shot peen forming

2022 ◽  
Author(s):  
Vladislav Sushitskii ◽  
Pierre-Olivier Dubois ◽  
Hong Yan Miao ◽  
Martin levesque ◽  
Frederick Gosselin
Keyword(s):  
Shot Peening ◽  
Pattern Generation ◽  
Experimental Results ◽  
Shape Model ◽  
Peen Forming ◽  
Metal Plates ◽  
Airplane Wing ◽  
Aluminum Plates ◽  
Doubly Curved

We present a methodology for automated forming of metal plates into freeformshapes using shot peening. The methodology is based on a simulation softwarethat computes the peening pattern and simulates the effect of its application.The pattern generation requires preliminary experimental characterizationof the treatment. The treatment is applied by a shot peening robot. The program for the robot is generated automatically according to the peening pattern. We validate the methodology with a series of tests. Namely, we form nine aluminum plates into doubly curved shapes and we also shape model airplane wing skins. The article describes the complete workflow and the experimental results.

Shaping of Ceramics Using Residual Stresses

2013 ◽  
Vol 768-769 ◽  
pp. 478-483
Author(s):  
Heiko Höpfel ◽  
Wulf Pfeiffer
Keyword(s):  
Shot Peening ◽  
Surface Region ◽  
Cyclic Strength ◽  
Common Procedure ◽  
Near Surface ◽  
Peen Forming ◽  
Deformation Work ◽  
Stress States ◽  
Underlying Mechanisms ◽  
Localized Plastic Deformation

Shot peening is a common procedure used to improve the static and cyclic strength of metal components and for forming of thin walled components. The underlying mechanisms are localized plastic deformation, work hardening and the introduction of compressive stresses into the near-surface region. During the last decade we have been establishing damage-free shot peening processes for brittle materials such as ceramics. Based on these results we are now developing processes for peen-forming of ceramic components. This paper describes the first successful experiments aimed at shaping ceramic specimens using shot peening. Strips of different thicknesses, made of silicon nitride ceramic, were shot-peened using different shot sizes, peening pressures and coverage. The residual stress-depth distributions were determined using X-ray diffraction. Based on the experimentally determined stress states, the curvatures of the strips were calculated analytically and using Finite Element calculations (FEM). The results of the curvature measurements and calculations agree well.

scholarly journals Pose Estimation of Uncooperative Unknown Space Objects from a Single Image

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Xiaoyuan Ren ◽  
Libing Jiang ◽  
Zhuang Wang
Keyword(s):  
Pose Estimation ◽  
Experimental Results ◽  
Single Image ◽  
Space Object ◽  
Shape Model ◽  
Structure Information ◽  
Space Objects ◽  
Specific Object ◽  
Unknown Objects ◽  
Unknown Object

Estimating the 3D pose of the space object from a single image is an important but challenging work. Most of the existing methods estimate the 3D pose of known space objects and assume that the detailed geometry of a specific object is known. These methods are not available for unknown objects without the known geometry of the object. In contrast to previous works, this paper devotes to estimate the 3D pose of the unknown space object from a single image. Our method estimates not only the pose but also the shape of the unknown object from a single image. In this paper, a hierarchical shape model is proposed to represent the prior structure information of typical space objects. On this basis, the parameters of the pose and shape are estimated simultaneously for unknown space objects. Experimental results demonstrate the effectiveness of our method to estimate the 3D pose and infer the geometry of unknown typical space objects from a single image. Moreover, experimental results show the advantage of our approach over the methods relying on the known geometry of the object.

scholarly journals Enhanced Corrosion Resistance of SA106B Low-Carbon Steel Fabricated by Rotationally Accelerated Shot Peening

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 872 ◽  
Author(s):  
Lei ◽  
Chen ◽  
Li ◽  
Chen ◽  
Yang
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Shot Peening ◽  
Low Carbon Steel ◽  
Experimental Results ◽  
Low Carbon ◽  
Tem Analysis ◽  
Electrochemical Tests ◽  
Micro Cracks ◽  
Cementite Dissolution

The corrosion resistance of a SA106B carbon steel with a gradient nanostructure fabricated by rotationally accelerated shot peening (RASP) for 5, 10, 15 and 20 min was investigated. Electrochemical tests were carried out in the 0.05 M H2SO4 + 0.05 M Na2SO4 and 0.2 M NaCl + 0.05 M Na2SO4 solutions. The experimental results showed that the sample RASP-processed for 5 min exhibited the best corrosion resistance among them. TEM analysis confirmed that the cementite dissolution and formation of nanograins, which improved the corrosion resistance of the steel. Prominent micro-cracks and holes were produced in the samples when the RASP was processed for more than 5 min, resulting in the decrease of corrosion resistance.

Laboratory Experiments in Fracture Propagation

1984 ◽  
Vol 24 (03) ◽  
pp. 256-268 ◽  
Author(s):  
W.L. Medlin ◽  
L. Masse
Keyword(s):  
Hydraulic Fracturing ◽  
Fracture Propagation ◽  
Fluid Viscosity ◽  
Confining Stress ◽  
Fracture Width ◽  
Metal Plates ◽  
Fracture Closure ◽  
Crack Volume ◽  
Aluminum Plates ◽  
Fracturing Experiments

Abstract This paper describes fracturing experiments in dry blocks of various rock materials. The results have application to evaluation of hydraulic fracturing theories. The block dimensions were 3 in.×4 in.×12 in. [7.6 cm×10.2 cm×30.5 cm] with metal plates epoxied to the 3-in.×12-in. [7.6-cm×30.5-cm] faces. Remaining faces were coated with soft epoxy to provide an impermeable jacket. The blocks were loaded in a pressure cell with an upper movable piston bearing on the 3-in.×4-in. [7.6-cm×10.2-cm] faces. A servo-controlled press applied constant stress to these faces higher than a lateral confining stress applied by oil pressure. Fractures were initiated by injection of various fluids into a small notch located on a center plane parallel to the 4-in.×12-in. [10.2-cm×30.5-cm] faces. Fracture growth along the same plane was assured by the stress conditions. Use of these experiments to test theories of fracture propagation required measurement of three variables, fracture width bi, and propagation pressure pi at the notch entrance, and fracture length, L. bi was determined by a capacitance method, and pi was measured directly by a pressure transducer. L was measured by two methods - either ultrasonic signals or pressure pulses generated in miniature cavities. The ultrasonic method confirmed the existence of a Barenblatt liquid-free crack ahead of the liquid front whose relative length decreased with confining stress. The metal plates bonded to the 3-in.×4-in. [7.6-cm×10.2-cm] faces prevented slip at the top and bottom of the fracture, giving a three-dimensional (3D) crack of constant height. However, the bi, pi, and L data followed trends predicted by two-dimensional (2D) (plane strain) elastic theory reasonably well. Fracture closure measurements after shut-in showed an initial period of leakoff-controlled closure and a final period of creep-controlled closure. A pi slope change at the transition is identified with the instantaneous shut-in pressure (ISIP) in field records and is higher than the true confining stress. Introduction Methods of predicting crack dimensions during fracturing operations are essential to proper design of field treatments. Many fracture-propagation theories have been advanced. Contributions have been made by Barenblatt,1 Khristianovitch and Zheltov,4,5 Howard and Fast,6 Perkins and Kern,7 LeTirant and Dupuy,8 Nordgren,9 Geertsma and de Klerk,10 Daneshy,11 and Cleary12,13 among others. However, practical methods of evaluating the theoretical work have been few. Mostly they have been. limited to indirect and generally inconclusive field evaluations. The Sandia mineback experiments14–16 have provided more direct evaluations. However, even here important fracturing parameters are uncontrolled or unknown. This paper describes laboratory-scale hydraulic fracturing experiments that provide critical data for evaluating crack propagation theories. In these experiments we measured the fundamental variables of crack growth under controlled conditions with known fracturing parameters. Experimental Methods All fracturing experiments were carried out in dry blocks 3 in.×4 in.×12 in. [7.6 cm×10.2 cm×30.5 cm] in size. Mesa Verde sandstone and Carthage and Lueders limestone were used as sample materials. Scaling considerations were important. It was necessary to scale down injection rate and leakoff to be consistent with fracture dimensions. The scaling factor of importance was taken to be fluid efficiency, the ratio of crack volume to injected volume. This factor was controlled through appropriate combinations of sample permeability and fracturing fluid viscosity. As fracturing fluids we used thick grease, hydraulic oils of various viscosities, and gelled kerosene (Dowell's YFGO™). Fluid efficiencies ranged from 3 to 70%. Most experiments were conducted at efficiencies between 30 and 50 %, a range typical of most field treatments. Fig. 1 shows the experimental arrangement. Shaped aluminum plates were bonded with Hysol clear epoxy to the 3-in.×12-in. [7.6-cm×30.5-cm] faces of the sample block as shown. The remaining faces were coated with a thin layer of the same epoxy to provide an impermeable jacket for confining pressure. One of the aluminum plates contained an injection port communicating with a 1.4-in. [0.64-cm] borehole as illustrated. A pair of brass plates with faces 0.2 in.×0.5 in. [0.5 cm×1.3 cm] was epoxied into the borehole at its center. These plates, separated by a gap of 0.01 in. [0.025 cm] served as a parallel plate capacitor. They were connected to a capacitance bridge that detected changes in gap width through changes in capacitance. This provided a direct, continuous measurement of fracture width at the borehole.

Underwater Explosive Welding of Thin Magnesium Plate onto some Metal Plates

2007 ◽  
Vol 566 ◽  
pp. 303-308
Author(s):  
Akihisa Mori ◽  
Kazuyuki Hokamoto ◽  
Masahiro Fujita
Keyword(s):  
Explosive Welding ◽  
Experimental Results ◽  
Welding Condition ◽  
Metal Plates ◽  
Wavy Interface ◽  
Welding Technique

Explosive welding of a thin magnesium plate onto some metal plates was performed by using underwater explosive welding technique developed by some of the authors. The experimental results show that the wavy interface which is typically found in the well-bonded clad was observed. The welding condition is discussed using the welding window based on the numerically simulated results using AUTODYN-2D code.

A Rudimentary Analysis of Improving Fatigue Life of Metals by Shot-Peening

1990 ◽  
Vol 57 (2) ◽  
pp. 307-312 ◽  
Author(s):  
Y. F. Al-Obaid
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Theoretical Analysis ◽  
Shot Peening ◽  
Reasonable Agreement ◽  
Experimental Results ◽  
Single Shot ◽  
Repeated Impact ◽  
Entire Surface ◽  
Complicated Process

In this paper, a rudimentary analysis of improving fatigue life of metals is presented. The process is viewed as one of repeated impact of a stream of hard shots on to a target. The model considers first a single shot impinging upon a target and, on bouncing, it leaves a residual stress below the surface of the target. The problem is then generalized to consider the effect of a stream of shots by assuming their effect to be uniformly distributed over the entire surface. The analysis is highly simplified and it mainly aims at understanding the mechanics of this complicated process. Although rudimentary, the theoretical analysis is seen to be in reasonable agreement with experimental results performed with shots on targets of various materials.

Experimental study of shot peening and stress peen forming

2010 ◽  
Vol 210 (15) ◽  
pp. 2089-2102 ◽  
Author(s):  
H.Y. Miao ◽  
D. Demers ◽  
S. Larose ◽  
C. Perron ◽  
Martin Lévesque
Keyword(s):  
Experimental Study ◽  
Shot Peening ◽  
Peen Forming

Deformation Behavior of Doubly Curved SS400 Thick Metal Plates by High Frequency Induction-Based Line Heating

2013 ◽  
Vol 535-536 ◽  
pp. 369-372 ◽  
Author(s):  
Kwang Seok Lee
Keyword(s):  
Numerical Analysis ◽  
Deformation Behavior ◽  
Thick Plate ◽  
Input Power ◽  
Line Heating ◽  
Metal Plates ◽  
Thermomechanical Deformation ◽  
Drastic Increase ◽  
Doubly Curved ◽  
Good Agreement

Line heating-induced deformation behavior of an SS400 thick plate was investigated through both numerical analysis and experimental counterpart by applying induction heating (IH) as a heat source. The drastic increase of temperature gradient upon increasing input power could mainly be predicted by numerical analysis, which attributes to the amount of permanent bending deformation of the thick plate. After plotting the amount of vertical deformation as a function of various positions from top surface of the plate, we found that the higher input power, the more thermomechanical deformation can be generated, regardless of the purposed doubly curved shapes such as concave and saddle-type plates. Also there is good agreement between the numerical analysis and experimental measurement in terms of the transverse curvature.

scholarly journals Nonlinear Guided Wave Tomography for Detection and Evaluation of Early-Life Material Degradation in Plates

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5498
Author(s):  
Chengwei Zhao ◽  
Sunia Tanweer ◽  
Jian Li ◽  
Min Lin ◽  
Xiang Zhang ◽  
...  
Keyword(s):  
Early Life ◽  
Guided Waves ◽  
Lamb Waves ◽  
Tone Burst ◽  
Guided Wave ◽  
Material Degradation ◽  
Third Order Elastic Constants ◽  
Metal Plates ◽  
Wave Tomography ◽  
Aluminum Plates

In this paper, the possibility of using nonlinear ultrasonic guided waves for early-life material degradation in metal plates is investigated through both computational modeling and study. The analysis of the second harmonics of Lamb waves in a free boundary aluminum plate, and the internal resonance conditions between the Lamb wave primary modes and the second harmonics are investigated. Subsequently, Murnaghan’s hyperelastic model is implemented in a finite element (FE) analysis to study the response of aluminum plates subjected to a 60 kHz Hanning-windowed tone burst. Different stages of material degradation are reflected as the changes in the third order elastic constants (TOECs) of the Murnaghan’s model. The reconstructed degradations match the actual ones well across various degrees of degradation. The effects of several relevant factors on the accuracy of reconstructions are also discussed.

Sign in / Sign up

Export Citation Format

Share Document