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    <title>Transport Research International Documentation (TRID)</title>
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    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
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    <item>
      <title>Optimization of Global and Local Formability Properties through Nb Microalloying</title>
      <link>https://trid.trb.org/View/2663544</link>
      <description><![CDATA[David Martin, CBMM Asia Bernardo Barile, CBMM Europe BV Caio Pisano, CBMM Europe BV  Automotive high strength steels have specific microstructure-dependent forming characteristics. Global formability is generally associated with high uniform strain values which imply good drawability and stretch forming properties driven by pronounced work hardening. Local formability on the other hand is often measured by various fracture strain values—generally higher in single phase steels. In this respect, the so-called ‘local/global formability map’ concept has been established not only to provide a comprehensive methodology to characterize existing automotive steels but also to enable improvement strategies toward more balanced forming characteristics. Niobium (Nb) microalloying is a powerful tool to achieve both property improvement in general and property balance in particular. More than two decades of research has demonstrated that Nb-induced microstructural optimization is applicable to HSLA steels, AHSS (DP, CP, TRIP, TWIP) and PHS, and it has been realized in commercial production of such steels. This contribution details the underlying metallurgical and processing effects of Nb microalloying in automotive high-strength steels and highlights achieved global and local formability improvements. Respective optimization vectors are demonstrated through intrinsic formability mapping, where the possibilities and limitations are indicated.]]></description>
      <pubDate>Mon, 02 Feb 2026 16:36:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2663544</guid>
    </item>
    <item>
      <title>Evaluating the Influence of Material Properties and Hardness on Tightening Torque</title>
      <link>https://trid.trb.org/View/2624009</link>
      <description><![CDATA[Earthmoving machines are equipped with a variety of ground-engaging tools that are joined by bolted connections to improve serviceability. These tools are made from heat-treated materials to enhance their wear resistance. Attachments on earthmoving machines, including buckets, blades, rippers, augers, and grapples, are specifically designed for tasks such as digging, grading, lifting, and breaking. These attachments feature ground-engaging tools (GET), such as cutting bits or teeth, to protect the shovel and other earthmoving implements from wear. Torquing hardened plates of bolted joint components is essential to ensure uniform load distribution and prevent premature failure. Therefore, selecting the proper torque is an important parameter. This study focuses on analyzing various parameters that impact the final torque on the hardened surface, which will help to understand the torque required for specific joints. Several other parameters considered in this study include hardware material, coefficient of friction, end bit and cutting-edge material, and their hardness. Understanding the influence of surface hardness on bolted joint torque is crucial for optimizing performance, reliability, and longevity of bolted connections in various engineering applications]]></description>
      <pubDate>Thu, 13 Nov 2025 16:07:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/2624009</guid>
    </item>
    <item>
      <title>Calibrating the combined hardening rule parameters for burr-free forging simulation of the torque rod joint</title>
      <link>https://trid.trb.org/View/2596709</link>
      <description><![CDATA[Joints used in the automotive industry are widely manufactured by forging. A cold upsetting process can provide burr-free forging which reduces economic loss by preventing material waste. In this study, finite element simulations for the upsetting of a torque rod joint made of 41Cr4 steel are performed. The novelty of the present study lies in the fact that the upsetting performance is investigated through simulation having hardening model in order to replace the existing forging process. The performance of hardening models is studied for an accurate simulation and optimum parameters are determined. A combination of the bilinear isotropic hardening rule and Chaboche’s nonlinear kinematic hardening rule is employed with the associated flow rule and Hill48 yield criterion to set up a plasticity model of the upsetting process for the first time. The parameters of the bilinear isotropic hardening rule are determined from monotonic tensile tests. The Chaboche’s parameters are determined by using hysteresis loops obtained from strain-controlled low-cycle fatigue tests. The parameters of both rules are combined. Furthermore, they are calibrated using inverse analysis based on the optimization method. Genetic algorithm is used for optimization. The experimental diameter and height measurements of the joint are compared with those obtained from the optimized model. The results show that the application of the combined hardening rule provides better prediction performance of the upset dimensions with minimum dimensional tolerance. The calibrated parameters are presented for the upsetting process. The calibrated parameters of the combined hardening model for the upsetting are YS = 446.64 MPa, TM = 3363.05 MPa, C₁ = 452.31 MPa, γ₁ = 55.165, C₂ = 212.13 MPa, γ₂ = 12.24, C₃ = 194.191 MPa, γ₃ = 10.00 where YS,TM,C₁,γ₁,C₂,γ₂,C₃,γ₃ are hardening models’ parameters. Absolute percent true error (APE) is 0.19%. The parameters are YS = 1.93 MPa, TM = 6.98 MPa, C₁ = 580.79 MPa, γ₁ = 1.08, C₂ = 597.23 MPa, γ₂ = 0.98, C₃ = 565.05 MPa, γ₃ = 2.87 in the case of cyclic load. APE is 1.66%. Also upsetting force requirement and material flow path are presented. The forging process can be replaced by the burr-free upsetting process with necessary changes in the die and press bench design. This replacement will save the 128-gr material per each one of the torque rod joint part.]]></description>
      <pubDate>Wed, 24 Sep 2025 15:31:09 GMT</pubDate>
      <guid>https://trid.trb.org/View/2596709</guid>
    </item>
    <item>
      <title>Microstructure, Tensile and Fracture Behaviors of Squeeze Cast Wrought Mg Alloy AZ80</title>
      <link>https://trid.trb.org/View/2558335</link>
      <description><![CDATA[Wrought magnesium alloy AZ80 with a thick section of 20 mm was prepared by squeeze casting (SC) and permanent steel mold casting (PSMC). The porosity measurements of the SC and PSMC showed that the SC AZ80 had a porosity of 0.52%, which was the 77% lower than that (2.21%) of the PSMC counterpart. The microstructure analyses and phase identification indicated that the cast AZ80 alloy consisted of a primary a-Mg phase, eutectic Mg-Al-Zn phases and Al-Mn intermetallic. The fine primary a-Mg dendrites and a high amount of the intermetallic phase were present in the SC AZ80 alloy. The yield strength (YS), ultimate yield strength (UTS), elongation (ef), elastic modulus (E) and strain hardening rate of the cast AZ80 specimens were evaluated by tensile testing. The measured engineering stress versus strain curves showed that the SC AZ80 alloy exhibited 84.68 MPa in YS, 168.23 MPa in UTS, 5.07% in ef, and 25.1GPa in modulus while the YS, UTS and ef of the PSMC specimen were only 71.61 MPa, 109.04 MPa, 1.85% and 21.9GPa. The calculated resilience and tensile toughness indicated that the SC AZ80 was more capable of resisting energy loads in elastic deformation and had an ability to absorb energy during plastic deformation than that of the PSMC AZ80. Also, the analyses of the true stress versus strain curves revealed that, upon the onset of plastic deformation, the strain-hardening rate of the SC AZ80 sample was 10,341 MPa, which was 9% higher than that (9,489 MPa) of the PSMC AZ80 specimen. The obtained mechanical properties showcased the fit of the casting process to wrought magnesium AZ80 alloy, which was squeeze casting. The low porosity level, fine dendritic structure and a high content of intermetallic phase should be somewhat responsible for high mechanical properties of the SC AZ80 alloy.]]></description>
      <pubDate>Tue, 27 May 2025 10:03:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/2558335</guid>
    </item>
    <item>
      <title>A New Methodology to Characterize the Influence of Paint Baking and Pre-Straining on the Tensile Properties of Third Generation Advanced High Strength Steels</title>
      <link>https://trid.trb.org/View/2539220</link>
      <description><![CDATA[The current ASTM A653 standard for determining the bake hardening index (BHI) of sheet metals can lead to premature fracture at the transition radius of the tensile specimen in high strength steel grades. In this study, a new test procedure to characterize the BHI was developed and applied to 980 and 1180 MPa third generation advanced high strength steels (3G-AHSS). The so-called KS-1B methodology involves pre-straining over-sized tensile specimens followed by the extraction of an ASTM E8 sample, paint baking and re-testing to determine the BHI. Various pre-strain levels in the range of 2 to 10% were considered to evaluate the KS-1B procedure with select comparisons with the ASTM A653 methodology for pre-strain levels of 2 and 8%. Finally, to characterize the influence of paint baking at large strain levels, sheared edge conical hole expansion tests were conducted. The tensile mechanical properties of the 3G steels after paint baking were observed to be sensitive to the pre-strain with bake hardening indices exceeding 100 MPa. However, the sheared edge formability was not significantly affected by paint baking.]]></description>
      <pubDate>Tue, 15 Apr 2025 13:56:47 GMT</pubDate>
      <guid>https://trid.trb.org/View/2539220</guid>
    </item>
    <item>
      <title>Effect of Hardening and Tempering Temperatures on the Mechanical
                    Behavior of Alloy Steel</title>
      <link>https://trid.trb.org/View/2511050</link>
      <description><![CDATA[Alloy steel possesses high strength, hardenability, fatigue strength, and good                     impact toughness. It is widely used for making various machine parts, automobile                     components, shafts, gears, connecting rods, and more. Hardening and tempering                     develop the optimum combination of hardness, strength, and toughness in                     engineering steel, thereby providing components with high mechanical properties.                     Hardening and tempering temperatures are crucial factors that affect the                     mechanical and metallurgical properties of 42Cr4Mo steel. In this research work,                     42Cr4Mo alloy steel samples were subjected to hardening and tempering processes.                     The hardening temperatures were set at 830°C, 850°C, and 870°C, while the                     tempering temperatures were maintained at 590°C and 650°C. The test results show                     that hardening at 830°C and tempering at 590°C achieve high tensile strength,                     which decreases as the temperature increases. Different hardening temperatures                     and constant tempering temperatures will be optimized to achieve the desired                     hardness, ultimate tensile strength, yield strength, impact resistance, and                     metallurgical properties. These parameters significantly contribute to                     determining the appropriate.]]></description>
      <pubDate>Tue, 18 Feb 2025 14:58:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/2511050</guid>
    </item>
    <item>
      <title>Study of Effect on Structural Strength of Locally Strengthened Rotor Lamination Stack through Virtual Validation</title>
      <link>https://trid.trb.org/View/2483080</link>
      <description><![CDATA[Rotor and Stator are the key constituents of an electric motor that are made of several laminates punched from a sheet metal and stacked together. The rotor stack is inserted with magnets at the punched-out pockets and is assembled with a shaft via press fitting. Rotor assembly being the rotating part of an E-Motor is subjected to centrifugal loads due to masses of magnets, lamination stack and shaft rotating at high speeds, temperatures and assembling loads because of which rotor laminates experience failures as the high strains develop in the regions on the laminate that support magnets. Typically, these high strain locations are the sections of the magnet pockets one on the outer diameter of the laminate and the other at the sections between the magnet pockets. Traditionally, these high strains are addressed by increasing the area of these sections, but this has a detrimental effect on the electromagnetic performance. Instead of increasing the area of these sections, the proposed solution of local strengthening of the magnet pockets influences strength of these sections of the lamination stack. Such localized strengthening can be achieved through surface hardening, grain boundary refinement or using high strength magnet inserts. In this paper, an approach for investigating the effect of localized hardening on improvement in strength of rotor laminate is studied using Finite Element Analysis. A comparison is made between the locally strengthened and non-strengthened rotor laminate in terms of deformations and strains.]]></description>
      <pubDate>Wed, 22 Jan 2025 16:59:26 GMT</pubDate>
      <guid>https://trid.trb.org/View/2483080</guid>
    </item>
    <item>
      <title>Springback Analysis with a Modified Hardening Model</title>
      <link>https://trid.trb.org/View/1787488</link>
      <description><![CDATA[Previously-reported draw-bend tests showed large discrepancies in springback angles from those predicted by two-dimensional finite element modeling (FEM). In some cases, the predicted angle was several times the measured angle. With more careful 3-D simulation taking into account anticlastic curvature, a significant discrepancy persisted. In order to evaluate the role of the Bauschinger Effect in springback, a transient hardening model was constructed based on novel tension-compression tests for three sheet materials: drawing-quality steel (baseline material), high-strength low-alloy steel, and 6022-T4 aluminum alloy. This model reproduces the main features of hardening following a strain reversal: low yield stress, rapid strain hardening, and, optionally, permanent softening or hardening relative to the monotonic hardening law. The hardening law was implemented and 3-D FEM was carried out for comparison with the draw-bend springback results. Marked improvement was obtained, particularly for large springback angles.]]></description>
      <pubDate>Wed, 22 Jan 2025 09:33:56 GMT</pubDate>
      <guid>https://trid.trb.org/View/1787488</guid>
    </item>
    <item>
      <title>Limit State of Bake Hardened Stamped Interstitial-Free Steel Automotive Parts Caused by Local Thickness Reduction</title>
      <link>https://trid.trb.org/View/2475788</link>
      <description><![CDATA[Current trends in the complex shapes of modern automobiles lead to the need for extremely formable materials for deep drawing applications. In general Interstitial–Free (IF) steels present the solution for this purpose. In addition, the cold stamping process is influenced by a variety of input factors that must be correctly adjusted. An imperfection in one of the inputs may cause stamping defects even with deep drawing materials. Limit states may then appear in the form of cracks or unacceptable thinning in the critically stressed areas of the stamped parts. For this reason, a general focus is placed on the use of non-destructive methods and inspection of stamped parts after stamping for potential subsequent modification of the stamping process. The presented work deals with the material analyses of stamped parts made of Bake-Hardened Interstitial-Free steel, including the local thickness reduction of the material, leading to the occurrence of crack propagation. The focus of the work was placed on the critical influencing factors resulting from the limit states presented. The evaluation of the material flow and the local plastic response was carried out using a cylindrical indentation method. In addition, the SEM analyses showed the importance of the deformation capacity of the surface coating which proved to be one of the decisive parameters for the occurrence of limit states.]]></description>
      <pubDate>Mon, 13 Jan 2025 08:59:38 GMT</pubDate>
      <guid>https://trid.trb.org/View/2475788</guid>
    </item>
    <item>
      <title>Effect on Ageing and Cerium Addition on Magnesium
                    Alloy</title>
      <link>https://trid.trb.org/View/2483085</link>
      <description><![CDATA[Magnesium (Mg) alloys are becoming ever more ubiquitous as the need for lighter                     and stronger alloys has increased significantly in the past decades. Mg alloy                     grade AZ91D is embedded in 0.5 of cerium have a high strength-to-weight ratio                     and lower specific density, which is useful in the case of automobile                     applications. An inconclusive study by Lagowski has shown that interrupted age                     hardening of AZ magnesium alloy increases the yield strength by around 10%. An                     investigation on the developed AZ91D+0.5Ce alloy subjected to various ageing                     treatments was carried out in this present study. The various aged samples were                     investigated by optical microscopy and scanning electron microscopy analysis.                     The yield strength was also evaluated quantitatively as a function of ageing                     parameters. A significant increase in yield strength and hardness values was                     observed in the artificially aged samples due to the precipitation of                         Mg17Al12 phases.]]></description>
      <pubDate>Mon, 30 Dec 2024 11:53:51 GMT</pubDate>
      <guid>https://trid.trb.org/View/2483085</guid>
    </item>
    <item>
      <title>Failure Prediction of Sheet Metals Based on an Anisotropic Gurson Model</title>
      <link>https://trid.trb.org/View/1787394</link>
      <description><![CDATA[A failure prediction methodology that can predict sheet metal failure under arbitrary deformation histories including rotating principal stretch directions and bending/unbending with consideration of damage evolution is reviewed in this paper. An anisotropic Gurson yield criterion is adopted to characterize the effects of microvoids on the load carrying capacity of sheet metals where Hill’s quadratic anisotropic yield criterion is used to describe the matrix normal anisotropy and planar isotropy. The evolution of the void damage is based on the growth, nucleation and coalescence of microvoids. Mroz’s anisotropic hardening rule, which was proposed based on the cyclic plastic behavior of metals observed in experiments, is generalized to characterize the anisotropic hardening behavior due to loading/unloading with consideration of the evolution of void volume fraction. The effects of yield surface curvature are also included in the plasticity model. Here, the Marciniak-Kuczynski approach or the initial imperfection approach is employed to predict failure/plastic flow localization by assuming a slightly higher initial void volume fraction inside randomly oriented imperfection bands in a material element of interest. The failure of sheet metals is reached when plastic localization becomes possible under a given deformation history. Applications of the failure prediction methodology to predict the sheet metal failure in a fender forming process and biaxial stretching processes with pre-bending/unbending are reviewed.]]></description>
      <pubDate>Mon, 23 Dec 2024 10:40:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/1787394</guid>
    </item>
    <item>
      <title>Comparison of Bake Hardening Effects on AHSSs and Extruded Aluminum Alloys Applied in BEV Reinforcement Structures</title>
      <link>https://trid.trb.org/View/2367705</link>
      <description><![CDATA[At the dawn of battery electric vehicles (BEVs), protection of automotive battery systems as well as passengers, especially from severe side impact, has become one of the latest and most challenging topics in the BEV crashworthiness designs. Accordingly, two material-selection concepts are being justified by the automotive industry: either heavy-gauge extruded aluminum alloys or light-gauge advanced high-strength steels (AHSSs) shall be the optimal materials to fabricate the reinforcement structures to satisfy both the safety and lightweight requirements. In the meantime, such a justification also motivated an ongoing C-STARTM (Cliffs Steel Tube as Reinforcement) Protection project, in which a series of modularized steel tube assemblies, were demonstrated to be more cost-efficient, sustainable, design-flexible, and manufacturable than the equivalent extruded aluminum alloy beams as BEV reinforcement structures. Tangent to this comparative study, the present work shed some light on the bake hardening (BH) effects during a paint-baking cycle, which was a necessary processing procedure for a body-in-white (BIW), on some representative AHSSs and extruded aluminum alloys via various coupon-level mechanical experiments under precise in-situ strain/displacement and temperature control conditions at multiple strain rates and stress states. The corresponding material mechanisms were also reviewed and explained. Eventually, the test results revealed some tremendously distinct changes induced by the BH effects on the two types of metallic materials: the baking-induced Cottrell atmosphere could effectively enhance the strength without weakening the local ductility of the target AHSS, while the baking-induced precipitation slightly hardened the selected aluminum alloy yet lowered its fracture limit. Such a distinction further indicated the advantages of the AHSSs in this application. The ultimate objective of this work was to provide relative references for future finite element simulations and BEV structural designs.]]></description>
      <pubDate>Tue, 16 Apr 2024 09:52:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/2367705</guid>
    </item>
    <item>
      <title>Numerical Studies on Effects of Various Factors on Residual Stress Distribution Characteristics in Induction Hardened Shafts</title>
      <link>https://trid.trb.org/View/2320578</link>
      <description><![CDATA[The authors constructed a numerical analysis model of hardness and residual stress distribution considering phase transformation during quenching. Using the model, they estimated distributions of hardness and residual stress in the induction hardened shaft. The accuracy of the model was confirmed by comparison with the experimental data. Moreover, through the numerical simulations of induction hardening under various conditions, the authors also considered the relationship between the case depth and the residual stress distribution.]]></description>
      <pubDate>Tue, 27 Feb 2024 16:40:18 GMT</pubDate>
      <guid>https://trid.trb.org/View/2320578</guid>
    </item>
    <item>
      <title>Prediction of Surface Finish on Hardened Bearing Steel Machined by
          Ceramic Cutting Tool</title>
      <link>https://trid.trb.org/View/2341686</link>
      <description><![CDATA[Prediction of the surface finish of hardened bearing steels was estimated in                     machining with ceramic uncoated cutting tools under various process parameters                     using two statistical approaches. A second-order (quadratic) regression model                     (MQR, multiple quantile regression) for the surface finish was developed and                     then compared with the artificial neural network (ANN) method based on the                     coefficient determination (R                     2), root mean square error (RMSE), and percentage error (PE). The                     experimental results exhibited that cutting speed was the dominant parameter,                     but feed rate and depth of cut were insignificant in terms of the Pareto chart                     and analysis of variance (ANOVA). The optimum surface finish in machining                     bearing steel was achieved at 100 m/min speed, 0.1 mm/revolution (rev) feed                     rate, and 0.6 mm depth of cut. In addition, the ANN model revealed a better                     performance than that of MQR for predicting the surface finish when machining                     the hardened bearing steels because R                     2 was about 0.787 and 0.903 for MQR and ANN, respectively. Besides,                     these were associated with RMSE of 0.302 and 0.1071 for MQR and ANN. Further, PE                     estimated from randomly selected data were about 25.56% and 10.86% for MQR and                     ANN, respectively. However, MQR presented the lowest error of 2.86%, but the                     highest error of 40.3%, while ANN indicated the lowest error of 0.11%, but the                     highest error of 37.0%, respectively.]]></description>
      <pubDate>Tue, 20 Feb 2024 10:04:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/2341686</guid>
    </item>
    <item>
      <title>A Comparative Analysis on Corrosion Behavior on Precipitation Hardened Stainless Steel Weldments for Car Parts</title>
      <link>https://trid.trb.org/View/2296612</link>
      <description><![CDATA[Precipitation Hardened Stainless Steel (PHSS) is one of the martensitic steels that possess exceptional strength and corrosion resistance. Because of its characteristics, this PHSS is exclusively adopted in numerous engineering uses such as nuclear, chemical and marine industries. Welding is one of the important methods of joining that helps to make weldments with better performance characteristics. Corrosion behaviour is one of the important characteristics that contribute hugely to marine and other corrosion-related environments and also this is the most common problem for most of the manufacturing industries. The goal of this study was to analyze the PHSS weldments’ corrosive behavior and compare it with that of the two commonly used welding processes, namely MIG and TIG. The corrosive properties of the weldments were evaluated using various mediums, such as nitric acid, ferric chloride, and Oxalic acid. The weight loss procedure was utilized to calculate the PHSS weldments’ corrosion rate. The results of the study revealed that the corrosion rate has increased with time. Temperature variations were identified as the primary cause of this phenomenon.]]></description>
      <pubDate>Tue, 28 Nov 2023 11:32:58 GMT</pubDate>
      <guid>https://trid.trb.org/View/2296612</guid>
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