Manufacturing Commons^™

From Strain To Stress: Stress Map Testing Of Almen Strips, Donovan Stumpf, Rajeshree Varma, Paul R. Mort

15th International Conference on Shot Peening

Almen strips have long been used to evaluate shot peening intensity, with arc height serving as a proxy for compressive residual stress. Stress mapping tests (SMT) in this work involve the controlled flattening of an Almen test strip onto a spatial pressure sensor, acting as an inferential measurement for the net bending moment caused by the relaxation of the peened strip. This work explores how stress mapping tests add insight into the stress state of Almen strips, potentially offering a fast and practical alternative to residual stress depth profiling. SMT data analysis provides a framework for relating Almen gauge height …

Fourier Analyses Of Optical Profilometry As An Inferential Measurement For Impact Coverage., Langdon Feltner, Paul Mort

15th International Conference on Shot Peening

A critical consideration in peening process design is achieving sufficient impact coverage. Conventional methods for assessing coverage rely on manual inspection, which is time-consuming and poorly suited for automated control. In this work, we investigate the use of frequency-domain analysis to quantify surface modification in peened samples using optical profilometry (OP) data. Three-dimensional surface maps of Almen strips were acquired using a high-resolution OP system and analyzed via fast Fourier transform (FFT) to compute spatial power spectral densities (PSDs). PSD maps and radially averaged profiles reveal consistent amplification of harmonic components similar to the nominal particle size, with increasing intensity …

Comparison Of Peening Effect Between Additive Manufacutred And Drawing Titanium Alloy, Hitoshi Soyama

15th International Conference on Shot Peening

Although additively manufactured (AM) metals are attractive materials, their remarkable weak fatigue properties are an obstacle to their practical application. Thus, post-processing to improve their fatigue properties is required. In the present study, powder bed fusion using laser sintering titanium alloy, i.e., PBF-LS/Ti6Al4V was treated by shot peening (SP), submerged laser peening (SLP), cavitation peening (CP), and fine particle bombarding (FPB), then the fatigue properties were investigated by a torsional fatigue test, comparing with drawing Ti6Al4V. It was revealed that the fatigue strength at 10⁷ was 446 ± 5 MPa for PBF-LS/Ti6Al4V treated by FPB+CP, 359 ± 9 MPa …

Reduced Order Approach For Peening Stress Field Variability, Langdon Feltner, Paul Mort

15th International Conference on Shot Peening

A common goal in shot peening research is to connect operational parameters to resultant residual stress fields, providing a means to control and optimize the effectiveness of surface treatment. In practice, experimental measurements of residual stresses are often averaged values over regions that are large in comparison to an impact dimple. In fact, the stochastic nature of impact locations leads to residual stress fields that are distributed. Finite element peening simulations confirm this observation. The goal of this report is to connect operational parameters to localized fluctuations in residual stress through probabilistic reasoning (Figure 1). In particular, the development of …

Investigations On The Fatigue Strength Of Threads Produced By Different Fabrication Techniques, Philippe Du Maire, Jürgen Hoffmeister, Andreas Öchsner, Michael Johlitz

15th International Conference on Shot Peening

The increasing importance of sustainability in engineering demands the development of long-lasting, high-performance components that reduce material and energy consumption over time. This study investigates how different thread manufacturing processes, i.e., cutting, rolling, and deep rolling, affect the fatigue strength of bolts made from 42CrMo4+QT steel. Cylindrical specimens with M12 threads were subjected to cyclic tensile loading with constant mean stress. Fatigue strength was evaluated using the staircase method, and supporting analyses included X-ray diffraction for residual stress, and full width half maximum examination and Vickers microhardness measurements. Results show that thread rolling significantly improves fatigue strength, achieving 113.8 MPa …

Effect Of Fine Particle Peening Induced Material Transfer On The Initial Deposition Behavior Of Nickel Electroplating On Aluminum Substrate, Kazuki Iijima, Yutaka Kameyama, Hideaki Sato, Shuhei Kodama

15th International Conference on Shot Peening

Plating on aluminum requires a complex zincate pretreatment. Fine Particle Peening (FPP), using particles ≤200 µm, has gained attention as an alternative due to its ability to transfer particle components onto the surface, potentially improving deposition and adhesion. Previous studies showed enhanced plating on aluminum treated with steel particles. This study investigates the effectiveness of FPP as a pretreatment for nickel electroplating by examining initial deposition behavior. A1050-H24 aluminum was treated using FPP with either steel or glass particles, compared to an untreated specimen. Steel particle FPP created a lamellar microstructure with alternating iron and aluminum phases. EBSD revealed that …

The Effect Of Surface Treatment On The Fatigue Strength Of Sus316l Additive Manufactured Products, Hitoshi Nishijima, Yuji Kobayashi, Toshiya Tsuji, Kiyotaka Masaki

15th International Conference on Shot Peening

Rotating bending fatigue tests were conducted to investigate the effect of shot peening and barrel finishing on fatigue properties of SUS316L made by laser PBF which was one of additive manufacturing processes. Surface roughness, residual stress, and fatigue strength were investigated for each specimen. As a result, the fatigue strength of the barrel finished specimens was almost same or better than that of the shot peened specimens. Barrel finished specimens increased 4.1 times higher fatigue strength than as-built specimens. The surface roughness of the specimens after barrel finishing was reduced by up to 96% compared to the as-built specimens. On …

Expansion Of Laser Peening Application With A High-Power Microchip Laser On A Robotic Arm, Yuji Sano, Yoshio Mizuta, Satoshi Tamaki, Tomonao Hosokai, Tomoharu Kato, Yoshihiro Sakino, Volker Schneidau, Sebastian Holz, Jörg Behler

15th International Conference on Shot Peening

Laser peening (LP) introduces compressive residual stress (RS) onto the surface of metallic materials using nanosecond laser pulses irradiated through a water layer, thereby effectively suppressing fatigue crack initiation. However, conventional LP systems require large, stationary setups, restricting their use to indoor environments. To overcome this limitation, a portable LP device featuring a finger-sized microchip laser mounted on a collaborative robot arm has been developed. Equipped with a compact power supply and a water circulation/recovery system, the device can operate on-site with minimal setup. Successful processing across various materials has confirmed both compressive RS induction and fatigue life extension. Notably, …

Effects Of Laser Peening On Fatigue Properties Of Welded Aluminum Thin Plates, Kiyotaka Masaki, Yoshio Mizuta, Satoshi Tamaki, Yuji Sano

15th International Conference on Shot Peening

To improve the fatigue properties of welded aluminum alloy thin plates used in transportation machinery, handheld laser peening (HH-LP) was applied to 2 mm-thick A5083-O specimens prepared by bead-on TIG welding. Conventional laser peening often causes warping in thin plates, but the HH-LP treatment using low-energy laser pulses avoids this problem. The HH-LP treatment introduced compressive residual stresses of over 200 MPa on the heat-affected zone (HAZ) of the welded specimens. Fatigue tests under plane bending conditions revealed that the HH-LP treatment significantly improved the fatigue strength of the welded specimens, achieving a level comparable to that of the base …

Evaluation Of Peening Intensity With Nozzle-Mounted Sensor During Processing, Akinori Matsui, Shuji Hayashida, Yuji Kobayashi

15th International Conference on Shot Peening

In recent years, digital technologies have been increasingly applied in manufacturing, including visualization and anomaly detection in production equipment. In shot peening, Peening Intensity is a key process control indicator, but its measurement requires significant manual effort. This study aims to evaluate the possibility of using an AE-sensor-mounted nozzle to estimate Peening Intensity. We conducted experiments comparing sensor outputs with experimented Intensity under controlled conditions. A strong correlation (R² ≥ 0.95) was observed, suggesting that Peening Intensity can be estimated via AE sensing. This approach may contribute to labor-saving and automation in shot peening processes.

Comparison Of Anti-Fouling Performance Of Textured Glass Surface Fabricated By Ductile-Mode Peening And Precision Grinding, Hayato Tagaya, Yutaka Kameyama, Shuhei Kodama, Hideaki Sato, Kento Shinagawa, Ayumu Sekiguchi, Seiji Hirai, Hitoshi Ohmori

15th International Conference on Shot Peening

Recently, there has been a growing demand for precision processing glass. In addition to dimensional accuracy, surface texturing to impart functional properties has attracted increasing attention. For example, anti-fouling performance against powder adhesion is required for cover glasses of solar cells. Powder adhesion is governed by van der Waals forces, which depend on the surface texture of the substrate, suggesting that surface structures influence adhesion behavior. Our previous study demonstrated that angled fine particle peening (FPP) could fabricate a nanoscale fine texture on glass surfaces through ductile-mode peening—glass processing without brittle fracture. In this study, the effect of surface texturing …

Microstructural Changes And Residual Stress Generation On The Periodically Patterned Surface Texture Fabricated By Angled Fine Particle Peening, Yutaka Kameyama, Hideaki Sato, Ryokichi Shimpo

15th International Conference on Shot Peening

Focusing on the potential of peening technology as a surface texturing technique, angled fine particle peening (angled-FPP) has been proposed to fabricate a specific periodical surface structure, which possibly provides various surface functions. It is necessary to further characterize the textured surface to earn more advantages from angled-FPP. Thus, in this paper, texture formation phenomena, residual stress, and microstructural changes were investigated on the angled-FPP specimens.

Improving Fatigue Strength And Life Of Single Crystal Cmsx-4, Jochen Peter Fuhr, Lloyd Hackel, Nicolau I. Morar, Noah Holtham, Keivan Davami, Montu Sharma, Rajkumar Roy

15th International Conference on Shot Peening

The deep penetration of laser peening (LP) and retention of residual stress at high temperature by LP is significant in improving fatigue life and strength of superalloys exposed to high temperature and corrosion. Single crystal CMSX-4, was evaluated for stress relaxation and both fatigue life and fatigue strength of material that was LP-treated compared to non-LP and shot-peened (SP) specimens. LP was done with multiple layers using a 20 J/pulse laser where the laser high energy enabled using a 5 mm spot size on the metal surface. Stress measurements by the slitting technique showed the plastic penetration depth exceeded SP …

Optimization Of Surface Integrity And Fatigue Life In Hard Turning Of K110 Tool Steel, Y. A. Mashal, Mohamed G. Yousef, M. H. El-Axir

Journal of Engineering Research

The influence of various machining process parameters on surface integrity elements (e.g. surface roughness and surface residual stress) and fatigue life of hard metals is an important area of engineering. This study investigates the effect of various turning parameters on the surface integrity and fatigue life of K110 hard tool steel. The determination of residual stress was performed by a non-destructive testing technique using X-ray diffraction analysis (XRD). The experimental work extended to perform fatigue experiments using rotary bending machine which was designed and manufactured to assess the fatigue behavior under rotating bending stresses. In this investigation, single optimization of …

Transparent Eeg Analysis: Leveraging Autoencoders, Bi-Lstms, And Shap For Improved Neurodegenerative Diseases Detection, Badr Mouazen, Ahmed Bendaouia, Omaima Bellakhdar, Khaoula Laghdaf, Aya Ennair, El Hassan Abdelwahed, Giovanni De Marco

Manufacturing & Industrial Engineering Faculty Publications

Highlights

• Novel hybrid architecture: Combined autoencoders with bidirectional LSTM networks for enhanced EEG signal classification, achieving 98% accuracy in distinguishing AD, FTD, and healthy controls.

• Explainable AI integration: Implemented SHAP (SHapley Additive exPlanations) framework to enhance model transparency and identify entropy as the most influential feature for neurodegenerative disease detection.

• Optimal temporal segmentation: Demonstrated that 5-s EEG windows with 50% overlap provide the best balance between classification accuracy and computational efficiency.

• Comprehensive feature extraction: Utilized Power Spectral Density (PSD) analysis across standard frequency bands (Delta, Theta, Alpha, Beta, Gamma) following autoencoder-based dimensionality reduction.

• Superior performance validation: Outperformed traditional machine learning …

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Using Statistical Clustering Of Trajectory Data To Support Analysis Of Subject Movement In A Virtual Environment, Martin Galicia Avila, Douglas Timmer, Alley C. Butler

Manufacturing & Industrial Engineering Faculty Publications

Gracia de Luna conducted experiments with an HMD virtual environment in which human subjects were presented with surprise distractions. His collected data for head, dominant hand, and non-dominant hand included 6 DOF human subject trajectories. This paper examines this data from 57 human subject responses to those surprise virtual environment distractions using statistical trajectory clustering algorithms. The data is organized and processed with a Dynamic Time Warping (DTW) algorithm and then analyzed using the Density Based Spatial Clustering (DBSCAN) algorithm. The K-means method was used to determine the appropriate number of clusters. Chi Squared goodness of fit was used to …

Recent Progress And Scientific Challenges In Wire-Arc Additive Manufacturing Of Metallic Multi-Material Structures, Sainand M. Jadhav, Sambhaji Kusekar, Akash Belure, Satyavan Digole, Abhijeet Mali, Muralimohan Cheepu, Manoj Mugale, Suhas Alkunte, Duckbong Kim

Faculty Articles

Metallic multi-material structures are heterogeneous structures characterized by changing composition, microstructures, and site-specific characteristics, advantageous for numerous applications where multifunctionality is desired. Metallic multi-material structures are known as bimetallic structures (BSs), which are functionally graded materials (FGMs). In recent years, wire-arc additive manufacturing (WAAM) advanced as a promising additive manufacturing process to realize the fabrication of these structures due to its high deposition rate, cost-effectiveness, and material utilization efficiency. This review presents a comprehensive overview of the recent progress, processing strategies, and scientific challenges in WAAM of multi-material structures. The paper begins with an introduction to multi-material structures, followed by …

Material Extrusion 3d Printing Of Metal Alloy: Material, Methods And Application., Sihan Zhang

Electronic Theses and Dissertations

Material extrusion (MEX) additive manufacturing presents a promising pathway for producing metal components with complex geometries while avoiding the safety hazards associated with loose powder handling in conventional metal additive manufacturing processes. This dissertation investigates the development and optimization of MEX processes for aluminum alloys, addressing critical challenges in feedstock formulation, printing parameter optimization, and post-processing strategies. Three distinct approaches were explored to advance the capabilities of aluminum MEX: filament-based processing of 6061 aluminum, paste-based extrusion of 6061 aluminum, and development of a novel aluminum-magnesium-tin alloy system for space manufacturing applications. The filament-based approach successfully demonstrated the production of 6061 …

Human Comfort Modeling, Measurement, And Improvement In Human–Robot Collaboration, Yuchen Yan

All Dissertations

A dissertation is proposed to explore human comfort in human-robot collaboration (HRC) through modeling, prediction, and enhancement methodologies. Human comfort is a crucial yet underexplored factor in HRC, directly influencing task efficiency, trust, and overall collaboration effectiveness. Understanding the influential factors, developing computational models, and refining methods to improve human comfort in HRC are essential steps toward advancing the field of collaborative robotics. To address these challenges, multiple studies have been conducted. A series of experimental studies were performed to investigate how robot motion-based parameters affect human comfort in HRC. These studies examined both analytical comfort modeling approaches and physiological …

Microstructural Investigation Of Graphene Reinforced Nickel Aluminum Bronze Prepared Via Laser Powder Bed Fusion, Wen Qian, Maxwyll Mcconnell, Jazmin Ley, Luke Schwaninger, Xin Chen, Bai Cui, Joseph A. Turner

Mechanical Engineering Faculty Publications

Nickel aluminum bronze (NAB) powders coated with reduced graphene oxide (RGO) were successfully fabricated using additive manufacturing (AM) via laser powder bed fusion. The resulting samples were characterized using a suite of complementary techniques, including x-ray diffraction, scanning electron microscopy, energy-dispersive x-ray spectroscopy, nanoindentation, x-ray computed tomography, and electron backscatter diffraction. These methods were employed to reveal the micro- and nanoscale features within the fine dendritic microstructure. The as-fabricated microstructures were observed to deviate significantly from typical as-cast configurations. In the AM RGO-coated NAB specimens, the formation of the κ_I phase was notably suppressed and is attributed to the …