Engineering Commons^™

Hydrogen Embrittlement In Shot-Peened Steel, Jia-Huei Tien, David R. Johnson, David Bahr

15th International Conference on Shot Peening

This work investigates the role of shot peening on hydrogen embrittlement resistance in quenched and tempered 1070 steel. Thermal desorption spectroscopy results revealed that shot-peened specimens contained nearly twice the hydrogen (H) content of unpeened samples when charged under the same electrochemical conditions, suggesting the introduction of additional trapping sites occur during peening. The mechanism underlying this behavior can be associated with increased dislocation density and is more consistent with the HELP mechanism. Residual stress measurements show a significant relaxation of compressive stresses in shot-peened specimen after H charging, indicating H enhanced dislocation rearrangement. Both unpeened and peened specimens exhibited …

Anisotropic Residual Stress Measurements In Additively Manufactured 316 Stainless Steel Parts, Rajeshree Varma, Donovan Stumpf, Paul R. Mort

15th International Conference on Shot Peening

Additive manufacturing (AM) using laser powder bed fusion (L-PBF) is increasingly used to produce complex parts for industries like aerospace and medical devices. The intrinsic characteristics of AM – layer-wise deposition and rapid thermal cycling – generate significant, anisotropic, residual stresses that can compromise part quality and performance. Recent studies highlight how these stresses are strongly influenced by process parameters and build orientation. X-ray diffraction (XRD) techniques, including sin²ψ and advanced two-dimensional approaches, have become the preferred methods for non-destructive, directionally resolved measurement of residual stress in AM metals. This review surveys advancements in XRD residual stress methods with a …

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 …

Enhancing High Cycle Fatigue Perfomance Of Electron Beam Melted Ti6al4v: A Study On Shot Peening And Hot Isostatic Pressing, Naghmeh M. Mojib, Dwayne D. Arola, Ramulu Mamidala

15th International Conference on Shot Peening

The qualification of electron beam powder bed fusion (PBF-EB) for safety-critical applications is hindered by variability in high cycle fatigue performance, largely due to surface roughness and internal defects. While Hot Isostatic Pressing (HIP) effectively reduces internal porosity, it does not address surface-initiated fatigue failures. This study investigated the combined effects of HIP and shot peening on enhancing the fatigue performance of PBF-EB Ti6Al4V. Over 50 specimens, including both vertical and horizontal build orientations, underwent high cycle fatigue testing per ASTM E466. X-Ray computed tomography confirmed decrease in defect distribution following HIP, while shot peening resulted in a more uniform …

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 …

Adaptation Of Shot Peen Parameters For Gear Geometry, David J. Breuer, Beth Matlock

15th International Conference on Shot Peening

Shot peening is a well established process for the surface enhancement of gearing. Gearing is a primary example of a high cycle fatigue application that can benefit from residual stress enhancement. Designing shot peening parameters to specific gear geometry based on material, heat treatment, and surface finish is a more precise way to achieve better performance outcomes. One of the best tools to assist in the optimal shot peening is x-ray diffraction (XRD) and its ability to measure small differences that can result in significant performance outcomes. XRD residual stress measurements are a direct measurement of elastic strain. The diffraction …

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 …

Numerical Assessment Of Shot Peening Contribution To The Fatigue Strength Of Gear Tooth Root, Gurutz Cortabitarte Laucirica, Xuban Telleria, Iñigo Llavori, Ibai Ulacia, Miren Larrañaga, Jon Ander Esnaola

15th International Conference on Shot Peening

Gears are commonly treated with shot peening (SP) and/or case hardening to enhance fatigue resistance. However, their effects are often conservatively assessed using standardized methods, which can limit their optimal application in industrial components. Particularly, the effect of SP over case-hardened gears remains insufficiently explored. Therefore, the present study evaluates the contribution of SP on single tooth bending fatigue (STBF) strength of raw and case-hardened spur gears, commonly used in automotive and heavy machinery industries. In the study four conditions are addressed: (i) untreated, (ii) case-hardened, (iii) shot-peened, and (iv) case-hardened and shot-peened. First, the residual stress field of the …

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 …

The Use Of A Dynamic Imaging System To Characterize Particle Size And Shape For Shot Peening Media, Matthew Spink, Tod Canty, Langdon Feltner, Paul Mort

15th International Conference on Shot Peening

Shot peening is a cold working process that enhances the mechanical properties of components such as springs, axles, and gears. Shot media are projected at a high velocity against the material’s surface, creating a layer of compressive residual stress that improves fatigue and wear resistance of the material. The size and shape of the media affect the residual stress layer that is created. To ensure consistent quality, it is critical to characterize and control the particle size and shape distribution of the shot media, both as-manufactured and in the working mix. This paper presents how the use of a dynamic …

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.

Roughness Parameters For Evaluating Blasted Or Shot Peened Surfaces, Stefanie Stoeckel, Sophie Groeger

15th International Conference on Shot Peening

A review of the papers presented at the last three International Conferences on Shot Peening revealed that the most used parameters are Ra and Rz. There has been comparatively little exploration of other parameters, particularly the S-parameters. Furthermore, the ISO 4287 standard for profile parameters was replaced by the new ISO 21920-2 standard in 2021. This is accompanied by the introduction of new parameters as well as alterations to existing ones. This paper demonstrates the limitations of Ra and Rz, as well as Sa and Sz, and explores additional areal and profile parameters that are useful for the description of …

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 …

Application Of Burnishing Process Expected To Frictional Heat To Non-Oriented Electromagnetic Steel Sheet, Yuji Kobayashi, Masato Okada

15th International Conference on Shot Peening

Burnishing is a technology used to improve the surface roughness of metals. On the other hand, it is expected that the metal structure near the surface will change due to strong distortion.

The magnetic properties of electromagnetic steel sheets depend on large crystal grains and fine crystals near the surface[1]. In particular, thinner fine crystal grain layers on the surface are expected to reduce iron loss. In this study, the power generation characteristics of Burnished electromagnetic steel sheets were evaluated.

Electromotive force waveform was evaluated by rotating the laminated electromagnetic steel sheets and using a spindle motor. The electromotive force …

The Effects Of Shot Peening Highly Loaded Compression Springs, David J. Breuer

15th International Conference on Shot Peening

The compression spring in this test study is typical of one used in a demanding off-road vehicle suspension. The cyclic loads applied during fatigue tests were severe enough to cause failure in approximately 11,000 cycles without shot peening.

The objectives of this study were the following: (1) Design a compression spring similar to those used in the off-road recreational industry. (2) Design & manufacture a fatigue test stand that could withstand high loads for months of testing. (3) Generate a matrix of shot peening treatments to produce different amounts of residual compressive stress. (4) Measure the shot peening residual compressive …

Nonlinear Analytical Models Of The Seismically Isolated ``Frame-Boiler'' System With Cantilever-Type Hysteresis Dampers, Aleksandr Mikhailovich Anushchenko, Dmitrii Evgenievich Bondarev, Aleksandr Yurievich Schukin

Journal of Sustainable Construction Materials and Technologies

This study shows results of development of the ``frame-boiler'' system with hysteresis dampers analytical model. Hysteresis dampers are used as boiler antiseismic bracing. It is noted that simplified analytical models are necessary at the stage of preliminary iterative calculations, when a CAE-modeling is impractical due to significant time costs. The authors have proposed 2 options of analytical models: 2-mass model and 3-mass model. The differential equations of motion for each model are written below. The results of the calculation for seismic impacts are compared with the finite element model. It is shown that 3-mass model gives good match of results …

Advancing Sustainable Structural Solutions: Hemp Fiber-Reinforced Polymer (Hfrp) Reinforcement Bars For Concrete Applications Through Material Selection, Simulation, And Pathways For Future Development, Thomas Cadenazzi, Busra Keles

Journal of Sustainable Construction Materials and Technologies

This paper investigates innovative Hemp Fiber-Reinforced Polymer (HFRP) rebars as a sustainable alternative to conventional Carbon Steel (CS) and Glass Fiber-Reinforced Polymer (GFRP) rebars used as reinforcement in concrete structures. The feasibility of HFRP rebars is assessed, focusing on mechanical properties and sustainability advantages. A virtual tensile test on a modeled M19 HFRP rebar, conducted using Autodesk's Fusion 360, demonstrates tensile strength comparable to CS 235 and greater environmental sustainability than GFRP, despite a slight reduction in stiffness. The study also considers the potential of graphene fiber integration to enhance mechanical properties, underscoring HFRP's adaptability. Findings suggest that HFRP rebars, …

Thermal Performance Variations Of Office Spaces In Educational Buildings Resulting From Façade Orientation: An Egyptian Case Stud, Hesham Safwat, Ahmad Elshamy, Rania Rushdy Moussa, Iman El-Mahallawi El-Mahallawi, Engy Elshazly, Mahmoud Mahmoudalghrieb

Mechanical Engineering

This paper investigates the thermal performance of an office floor within the Faculty of Engineering at the British University in Egypt (BUE), located in Cairo, a city characterized by a hot arid climate. The study focuses on understanding the building’s thermal behavior by comparing two identical office rooms: Room 212 (north-facing) and Room 201 (south facing). Utilizing dynamic thermal simulations with TRNSYS 18 for a full year, the research specifically analyzes the impact of these opposite orientations on indoor space temperature, total cooling loads, the monthly heat absorbed by various building surfaces, and the heat absorbed per unit area for …

Overcoming Variable Illumination In Photovoltaic Snow Monitoring: A Real-Time Robust Drone-Based Deep Learning Approach, Amna Mazen, Ashraf Saleem, Kamyab Yazdipaz, Ana Dyreson

Michigan Tech Publications

Snow accumulation on photovoltaic (PV) panels can cause significant energy losses in cold climates. While drone-based monitoring offers a scalable solution, real-world challenges like varying illumination can hinder accurate snow detection. We previously developed a YOLO-based drone system for snow coverage detection using a Fixed Thresholding segmentation method to discriminate snow from the solar panel; however, it struggled in challenging lighting conditions. This work addresses those limitations by presenting a reliable drone-based system to accurately estimate the Snow Coverage Percentage (SCP) over PV panels. The system combines a lightweight YOLOv11n-seg deep learning model for panel detection with an adaptive image …

Performance Of A Two-Body Wave Energy Converter With An Annular Heave Plate, Raj Tamakuwala, Muhammad Usman, Nathan Tom, Hassan Masoud

Michigan Tech Publications

We theoretically examine the performance of a two-body wave energy converter (WEC) featuring a floating sphere and a submerged annular heave plate, connected by a power take-off (PTO) system. Utilising linear wave theory, we derive the system's frequency-domain response to regular plane waves and analyse the impact of varying disk porosity on power generation. Our results suggest that annular disks can enhance power extraction efficiency in various cases compared with solid heave plates. Additionally, permeable plates can broaden operational conditions by reducing oscillation amplitudes and decreasing the mechanical strain on the PTO system without substantially compromising the power conversion efficiency. …

Heat Transfer Enhancement In Cold Plate Heat Exchangers With Trapezoidal Vortex Generators, Montgomery Miller

Student Theses and Dissertations

An experimental investigation was carried out to study the effects of trapezoidal vortex generators (VGs) as a method of thermal enhancement within cold plate heat exchangers. Three different cold plates were imbedded with VGs in the bottom of the flow passage of varying sizes (h/H = 0.195, 0.253, 0.36) and quantity, as well as a cold plate with no VGs to be used as a comparative baseline. Testing was conducted under the laminar, transitional, and turbulent flow regime (Re = 1000 to 5500) using distilled water as the coolant. Experimental results indicate that the addition of VGs provide a positive …

Development Of An Instrumented Test System To Evaluate Mechanical Characteristics Of Belted Conveyor Systems, Coleman Emerson Wilson

Student Theses and Dissertations

The use of conveyor systems within industrial and warehouse settings gives the ability for increased productivity and increased speed of moving objects. As in many settings, the use of these conveyor systems requires large amounts of continuous runtime, and the ability to save even small amounts of energy over a large period can create large improvements in the total overhead cost of running the facility. Research into the ability to characterize the components within a conveyor system gives the ability to identify sources of large amounts of wasted energy and quantify these losses. There is a need to quantify the …

Comparative Analysis Of Belt-Slider Pan Configurations On The Power Consumption Of Belted Conveyor Systems, Asib Ridwan

Student Theses and Dissertations

Conveyor systems are widely used in industrial applications for material handling, but their high energy consumption remains a significant challenge. This study investigated the influence of different belt-slider pan configurations on conveyor power consumption, aiming to optimize efficiency while minimizing energy losses. Three types of slider pans; mild steel, galvanized steel, and powder-coated steel, were analyzed under controlled experimental conditions to determine the motor torque and power consumption of a test conveyor system under various loading conditions. Torque and power values were derived, plotted, and comparatively analyzed across all configurations to determine performance differences. Static friction coefficients of each type …