Calibration Coefficients Determination Through Fem Simulations for the Hole-Drilling Method Considering the Real Hole Geometry

Blödorn, Rodrigo; Bonomo, Lucas A.; Viotti, Matı́as R.; Schroeter, Rolf Bertrand; Albertazzi, Armando

doi:10.1007/s40799-016-0152-3

Cited by 18 publications

(21 citation statements)

References 12 publications

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“…Finite element simulations have been utilized in several studies [22,30] and have provided reliable determinations of the calibration coefficients. The superposition approach has shown good estimation in most of these attempts, by considering the main strains of the drilled layer along with the effect of the removed layer, as explained in Section 2.…”

Section: Numerical Modeling Of the Calibration Processmentioning

confidence: 99%

“…However, these coefficients were good only for a particular type of material with particular experimental parameters. Blodorn et al [22] determined the calibration coefficients numerically using finite element modeling (FEM). A blind hole was created in the workpiece, and the load was applied to trigger the element displacement and determine the coefficients.…”

Section: Introductionmentioning

confidence: 99%

“…Significant differences were detected between the obtained coefficients and the standard (i.e., experimentally evaluated) values. Different finite element approaches were reported in [1,[23][24][25], including subjecting the loads on the internal surfaces of the created hole, and in [20,22,26], considering loads that act on the external borders of the specimens. Although several approaches have been implemented to find the coefficient numerically, there was no validation or confirmation of the precision of the measured stresses.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

On the Sensing and Calibration of Residual Stresses Measurements in the Incremental Hole-Drilling Method

Ammar

Shirinzadeh

Lai

et al. 2021

Sensors

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The current study presents three calibration approaches for the hole-drilling method (HDM). A total of 72 finite element models and 144 simulations were established to calibrate the measurements of the strain sensors. The first approach assumed the stresses acted on the boundaries of the drilled hole and thus analyzed the surrounding displacements field. The second analysis considered the loads on the outer surfaces of the specimen while measuring the strains’ differences between the model with and without the drilled hole. The third approach was more comprehensive as it considered the mechanical and thermal effects of the drilling operations. The proposed approaches were applied to two different materials (AISI 1045 and CFRP). The steel specimens were machined using a CNC lathe while the composite laminates were manufactured using the robotic fiber placement (RFP) process. Subsequently, the residual stresses (RSs) were measured using the HDM. The obtained data were compared with X-ray diffraction measurements for validation. The results showed better estimation of the RSs when utilizing the third approach and clear underestimation of the stresses using the second approach. A divergence in RSs values between the three approaches was also detected when measuring the stresses in the internal layers of the composite laminates.

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Section: Numerical Modeling Of the Calibration Processmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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On the Sensing and Calibration of Residual Stresses Measurements in the Incremental Hole-Drilling Method

Ammar

Shirinzadeh

Lai

et al. 2021

Sensors

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“…By introducing the gage circle diameter, the drilled hole diameter and the bottom-hole fillet radius, the authors developed a method based on the correction of acquired strains. Subsequently, Blödorn et al [19] recalculated the ASTM E837 coefficient for blind uniform stress using an FEM model with a hole bottom chamfer.…”

Section: Hole Bottom-chamfer Error: Description and Possible Correctionmentioning

confidence: 99%

“…To obtain measurements that are more accurate, it is therefore necessary to use calibration coefficients that consider the presence of the chamfer at the bottom of the hole. This source of error will be examined in greater detail, considering the proposed calibration coefficients to take this effect into account [17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Recent Advancements in the Hole-Drilling Strain-Gage Method for Determining Residual Stresses

Valentini¹,

Bertelli²,

Benincasa³

et al. 2020

New Challenges in Residual Stress Measurements and Evaluation

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The hole-drilling Strain-Gage method is a widely used and cost-effective technique for the evaluation of residual stresses. The test method is standardized by ASTM E837-13a, which defines the scope, measurement range, minimum requirements of instrumentation, test procedure, and algorithms and coefficients for the computation of uniform and non-uniform stress distribution. However, the standardized test method presents some limitations regarding the scope and measurement range; moreover, some typical errors involved in the measurements are not taken into account, i.e., errors due to the hole eccentricity, the local plasticity, the intermediate thickness, and the hole-bottom chamfer, which can affect the results in some cases. Also, the standard does not provide the user with a complete guide regarding the evaluation of the uncertainty connected with this type of measurement. The paper presents a more general approach that allows the correction of some errors and overcomes and some limitations of the ASTM E837-13a test method, contributing to greater accuracy of the test results.

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Evaluation of robotic fiber placement effect onprocess‐inducedresidual stresses using incrementalhole‐drillingmethod

Ammar

Shirinzadeh

2022

Polymer Composites

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The robotic fiber placement (RFP) process depends on continuous fusion bonding and solidifying of prepreg tows onto a substrate by subjecting them to a compression force and heat flux. However the advantages provided when using the RFP to fabricate the composite structures, it has adverse effects due to the induced residual stresses (RSs). The current work presents the effect of the RFP on the induced RSs in thermoset composites. RFP is utilized to fabricate specimens from carbon fiber reinforced polymers. Effects of placement speed, compression force, heating temperature, heating gas flowrate, and the location of the heat flux outlet nozzle are all included in the present study. A total of 69 flat panels are manufactured under different process conditions. Subsequently, the in‐depth RSs are measured using the incremental hole‐drilling method. Besides, the microstructures of the samples are also analyzed. The results show that the change in process parameters could significantly affect the induced RSs of the thermoset composites. Subjecting the samples to higher thermal and pressure loads would induce more RSs, which are attributed to the occurrence of partial curing during the manufacturing process along with the change in laminate geometry and porosity.

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Calibration Coefficients Determination Through Fem Simulations for the Hole-Drilling Method Considering the Real Hole Geometry

Cited by 18 publications

References 12 publications

On the Sensing and Calibration of Residual Stresses Measurements in the Incremental Hole-Drilling Method

On the Sensing and Calibration of Residual Stresses Measurements in the Incremental Hole-Drilling Method

Recent Advancements in the Hole-Drilling Strain-Gage Method for Determining Residual Stresses

Evaluation of robotic fiber placement effect onprocess‐inducedresidual stresses using incrementalhole‐drillingmethod

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