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    <title>Transport Research International Documentation (TRID)</title>
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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>
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      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>Heat Straightening Repair in Connecticut</title>
      <link>https://trid.trb.org/View/2566904</link>
      <description><![CDATA[The proposed research aims to establish the Connecticut Department of Transportation (CTDOT)’s own heat straightening repair guidelines and protocols. Additionally, the establishment of a dedicated heat straightening training program to equip CTDOT's engineers and contractors with the necessary skills and knowledge is to be proposed. For this research, an evaluation of the current conditions of heat straightening repair in New England, with a primary focus on Connecticut is to be performed. Through visits, surveys of the Department of Transportations (DOTs), and analysis of repair sites and previous damage-repair databases, the research seeks to enhance understanding of the most frequently damaged steel bridge types and the extent of damage in the region.]]></description>
      <pubDate>Wed, 18 Jun 2025 13:59:44 GMT</pubDate>
      <guid>https://trid.trb.org/View/2566904</guid>
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    <item>
      <title>Performance of Steel Bridge Girders Subjected to Damage and Heat Straightening Repair</title>
      <link>https://trid.trb.org/View/2209180</link>
      <description><![CDATA[This paper focuses on the heat straightening repair and rehabilitation of steel bridge girders damaged by collision with overheight trucks. The paper presents an numerical approach for simulating the damage, and the heat straightening repair of composite steel bridge girders. This approach is used to investigate the effects of damage followed by heat straightening repair on the: (a) residual stresses, (b) serviceability, and (c) ultimate load capacity of composite steel girders and bridges. Additionally, the effects of steel material and girder geometric properties, damage magnitude and location, and heating patterns and distribution are also evaluated. The results from the numerical parametric studies provide guidelines for designing heat straightening repairs, estimating final residual stresses, and evaluating the state (performance) of damaged-repaired steel bridges. These results are based on simulation only, and need further experimental investigations and validation, which is ongoing.]]></description>
      <pubDate>Tue, 22 Oct 2024 15:57:24 GMT</pubDate>
      <guid>https://trid.trb.org/View/2209180</guid>
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    <item>
      <title>Investigation of Thermal Effects of Flame Straightening on High-Strength Steels</title>
      <link>https://trid.trb.org/View/1973469</link>
      <description><![CDATA[The use of high-strength steels in the automotive industry is increasing. In many cases, the use of flame straightening to reduce deformation after welding is unavoidable in the manufacture of trailers, semitrailers, heavy vehicles, earthmoving machinery, military bridges etc. Due to the not very concentrated but relatively high temperature heat source, the process can cause significant changes in the microstructure which can endanger the safe use of these steels. This may be particularly true for the high-strength steels tested, for which we have very little experience and concrete measurement results. Due to the different thermal-physical properties of the flammable gases, the resulting heat effect varies depending on the gas and technology used. Nowadays, there is a lack of studies that analyse the effect of these types of heat cycles. During the experiments, the authors investigate the changes of the microstructure and mechanical properties caused by heat effect on unalloyed structural and high strength steels (S355J2+N, S690QL). The situation is complicated by the fact that manual technology typically also carries a high risk of local overheating, which can cause heat effects that are too long in time and/or too high temperature. In addition to the direct thermal effect study, a Gleeble 3500 thermomechanical physical simulator was used to perform thermal cycles measured during the technology. Two heating flames (acetylene/oxygen, propane/oxygen), three characteristic peak temperatures (1000 °C, 800 °C and 675 °C) and two types of cooling conditions (air cooling and intensive water cooling) were studied. Both the real direct thermal effect study and physical simulation showed a clear negative effect of overheating and intensive water cooling for the exanimated steels.]]></description>
      <pubDate>Mon, 11 Sep 2023 11:39:32 GMT</pubDate>
      <guid>https://trid.trb.org/View/1973469</guid>
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    <item>
      <title>Manual for Heat Straightening, Heat Curving and Cold Bending of Bridge Components</title>
      <link>https://trid.trb.org/View/2219421</link>
      <description><![CDATA[The objective of this manual is to provide a comprehensive reference on aspects of heat straightening, heat curving and cold bending as they pertain to steel bridge components. This manual is targeted towards both engineers and steelwork practitioners. This manual is an updated version of Federal Highway Administration (FHWA) Report, FHWA-IF-99-004, “Heat Straightening Repairs of Damaged Steel Bridges: A manual of Practice and Technical Guide” and FHWA Report, FHWA-IF-09-999, “Guide for Heat-Straightening of Damaged Steel Bridge Members” and includes various updates and suggestions developed from recent studies and investigations.]]></description>
      <pubDate>Mon, 07 Aug 2023 08:44:29 GMT</pubDate>
      <guid>https://trid.trb.org/View/2219421</guid>
    </item>
    <item>
      <title>Thermal Straightening Control System for Variable-Section Automotive Leaf Springs Rolling Based on IoT Edge Computing</title>
      <link>https://trid.trb.org/View/1959631</link>
      <description><![CDATA[With the rapid development of social economy in recent years, people’s living standards are also improving. The use of automobiles is becoming increasingly frequent, and people’s requirements for the safety, comfort, and energy saving of automobiles are also getting higher. This paper mainly studies the thermal straightening control system after the rolling of variable-section automotive leaf springs through edge computing based on the Internet of Things. This paper presents the basic concepts of IoT edge computing and the role they play in various aspects. The percentage of IoT development trends in 2011 was 6.7%. By 2020, the development trend percentage of IoT reached 68%, an increase of 61.3%. It can be seen that the development of the Internet of Things is very rapid. It can be seen that the straightening accuracy of the thermal straightening control system based on edge computing after the rolling of variable-section automotive leaf springs reaches 78%, and it is 29% higher than the traditional system straightening accuracy, which is only 49%. The safety of the thermal straightening control system of the variable-section automotive leaf spring after rolling based on edge computing reaches 95%, which is 33% higher than the safety of the traditional system. The thermal alignment control system for variable-section automotive leaf springs after rolling based on the edge computing of the Internet of Things is not only safer than the traditional system but also much higher in comfort and alignment accuracy than the traditional system. It can be seen that the thermal straightening control system for variable cross section automotive leaf springs after rolling based on IoT edge computing is more conducive to the development of the automotive industry.]]></description>
      <pubDate>Tue, 31 May 2022 09:15:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/1959631</guid>
    </item>
    <item>
      <title>Guide for Heat-Straightening of Damaged Steel Bridge Members: Final Draft of the AASHTO Guidelines</title>
      <link>https://trid.trb.org/View/1743949</link>
      <description><![CDATA[The purpose of this document is to provide comprehensive guidelines on heat straightening repair techniques for damaged steel bridge members. This Guide is a condensed and updated version of the previous Federal Highway Administration (FHWA) Report, FHWA-IF-99-004, “Heat-straightening Repairs of Damaged Steel Bridges, A Manual of Practice and Technical Guide”, which is proposed to become an AASHTO Guide, and is also listed as a standalone Manual on the FHWA website.]]></description>
      <pubDate>Sun, 25 Oct 2020 17:39:24 GMT</pubDate>
      <guid>https://trid.trb.org/View/1743949</guid>
    </item>
    <item>
      <title>Effects of Imperfections in Heat Straightening Repair of Steel Beam Bridges</title>
      <link>https://trid.trb.org/View/1495127</link>
      <description><![CDATA[A 40 ft. long two-span continuous steel bridge with two composite beams was constructed in the laboratory and subjected to damage followed by heat straightening repair. A36 steel section (W30 × 90) was used for the main girders (beams). Four spans (specimens) of the test bridge were statically damaged at each midspan using a hydraulic actuator, and subsequently repaired by applying Vee heats and restraining forces in the damaged region. Restraining force magnitude (corresponding to 0.4 Mp: 6.2 kips and 0.6 Mp: 9.5 kips), maximum heating temperature (800°F, 1200°F, and 1400°F), and the number of multiple damage-repair cycles (one and three cycles) were considered as the test parameters. The steel material properties were measured by taking samples from the repaired areas, and compared with undamaged steel material properties. Samples taken from specimens subjected to overheating (up to 1400°F) had similar structural properties and fracture toughness values as those taken from specimens subjected to normal heating (up to 1200°F). Specimens repaired with overstraining (0.6 Mp) combined with underheating (up to 800°F) required the largest number of heating cycles to fully repair the same damage. The fracture toughness of samples taken from specimens subjected to multiple (three times) damage-repair cycles was lower (decreased to about 84%) than the fracture toughness of samples taken from specimens subjected to only one damage-repair cycle. Therefore, multiple heat straightening repairs of a damaged beam should be performed with caution. With reference to serviceability performance for AASHTO HL-93 live load, the midspan deflections of beam specimens subjected to damage and heat straightening repair were comparable to those of undamaged beam specimens.]]></description>
      <pubDate>Tue, 20 Mar 2018 17:08:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/1495127</guid>
    </item>
    <item>
      <title>New Method of Car Body Panel External Straightening: Tools of Method</title>
      <link>https://trid.trb.org/View/1403823</link>
      <description><![CDATA[Recently repair and recovery vehicle body operations become more and more popular. A special place here is taken by equipment that provides performance of given repair operations. The most interesting things are methods for recovery of car body panels that allow the straightening without disassembling of car body panels and damaging of existing protective coating. Now, there are several technologies for repair and recovery of car body panels without their disassembly and dismantling. The most perspective is magnetic-pulse technology of external noncontact straightening. Basics of magnetic-pulse attraction, both ferromagnetic and nonferromagnetic thin-walled sheet metal, are explored. Inductor system calculation models of magnetic-pulse straightening tools are presented. Final analytical expressions for excited efforts calculation in the tools under consideration are introduced. According to the obtained analytical expressions, numerical evaluations of excited forces were executed. The volumetric epures of the attractive force radial distributions for different types of inductors were built. The practical testing of magnetic-pulse straightening with research tools is given. Using the results of the calculations the authors can create effective tools for an external magnetic-pulse straightening of car body panels.]]></description>
      <pubDate>Thu, 28 Apr 2016 14:42:59 GMT</pubDate>
      <guid>https://trid.trb.org/View/1403823</guid>
    </item>
    <item>
      <title>Guide for Heat-Straightening of Damaged Steel Bridge Members</title>
      <link>https://trid.trb.org/View/1308581</link>
      <description><![CDATA[Damage caused by overload, vehicle impact, handling, earthquake, or fire is a perennial problem associated with steel bridge structures. For almost half a century, heat-straightening techniques have been applied to bends and distortions in order to restore the original shape of steel elements. A few craftsmen, who have years of experience with heat straightening, perform the technique in the field with varying degrees of success. Some of these experts have mastered heat straightening, but the process is still considered more of an art than a science. The ability to repair damaged structural steel members in place, often without the need for temporary shoring, has generated interest in heat straightening from the engineering profession. However, engineers have had to rely primarily on their own judgment and the advice of experienced technicians in applying heat-straightening techniques. Two key questions have often been raised: Do heat-straightening procedures exist which do not compromise the structural integrity of the steel? And if so, how can such repairs be engineered to ensure adequate safety of the repaired structure, both during and after repair? The primary goal of this guide is to answer these two questions. This guide is intended for a general audience ranging from heat-straightening practitioner, to contractor, to inspector, and to bridge engineer.]]></description>
      <pubDate>Wed, 28 May 2014 15:26:28 GMT</pubDate>
      <guid>https://trid.trb.org/View/1308581</guid>
    </item>
    <item>
      <title>Effects of Realistic Heat Straightening Repair on the Properties and Serviceability of Damaged Steel Beam Bridges</title>
      <link>https://trid.trb.org/View/1266683</link>
      <description><![CDATA[The permanent deformations in steel beam bridges caused by collision with high profile vehicles can be repaired by heat straightening, which is a structurally efficient and cost-effective repair process developed by many engineers over the years. Guidelines for conducting heat straightening repair have been developed by the Federal Highway Administration (FHWA) and many state departments of transportation (DOTs). The guidelines establish limits for: (a) the maximum damage that can be repaired, (b) the maximum restraining force, and (c) the maximum heating temperature to prevent the side effects of heat straightening repair process. However the heat straightening guidelines are violated in the field due to time and economic issues. These violations include, but are not limited to: (a) underheating below 1200°F, (b) overheating above 1200°F, (c) overstraining above restraining force limit (0.5 Mp) and (d) multiple heat straightening of the same beam more than two times. Currently, there is a lack of knowledge of the effects of these imperfections in the heat straightening repair process on the condition and serviceability of the damaged-repaired beams. This knowledge is needed to develop more realistic guidelines for evaluating and replacing bridge members subjected to damage followed by imperfect heat straightening repair. The overall goal of this research is to develop recommendations and guidelines for evaluating steel beam bridges in Indiana subjected to damage followed by heat straightening repair with imperfections (overstraining, overheating, or multiple heat straightening).]]></description>
      <pubDate>Tue, 05 Nov 2013 20:14:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/1266683</guid>
    </item>
    <item>
      <title>Heat-Straightening Repair of Damaged Steel Bridge Girders</title>
      <link>https://trid.trb.org/View/885661</link>
      <description><![CDATA[This article describes the best uses and the limits of heat-straightening repair when applied to steel bridge girders that have been damaged, typically when a vehicle strikes a member such as a hanger in a through truss. This article gives additional information about the subsequent fatigue and fracture performance of heat-straightened bridge members, in order to better show when heat-straightening can be an economical and safe alternative repair strategy. This is based on the results of NCHRP project 10-63, which was initiated: to determine the effects of repeated damage and heat straightening, to identify and quantify material and process parameters limiting its effectiveness, and to establish guidelines, including limits on the damage and number of damage/repair cycles. Damage was simulated with a very large weight-drop machine designed for this project. The various scenarios tested are described, along with results. They include: useful inspection techniques, “pre-repair” repairs, repair of transverse stiffener details, influence of residual damage, and influence on fatigue life.]]></description>
      <pubDate>Mon, 30 Mar 2009 13:36:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/885661</guid>
    </item>
    <item>
      <title>Effects of Fabrication Procedures and Weld Melt-Through on Fatigue Resistance of
Orthotropic Steel Deck Welds</title>
      <link>https://trid.trb.org/View/878416</link>
      <description><![CDATA[Orthotropic bridge decks are commonly fabricated using 80% partial-joint-penetration groove welds (PJP) to join closed ribs to a deck plate. Because a tight fit may not always be achievable, weld melt-through is difficult to avoid and fatigue resistance may result. This report presents a study in which six 2-span, full-scale orthotropic steel deck specimens were built and tested to study the effects of  weld melt-through and distortion control measures on the fatigue resistance of closed rib-to-deck PJP welds. Three of the specimens were heat straightened, while the other three were pre-cambered to minimize the need for subsequent heat straightening. Based upon test results, it was determined that effective pre-cambering is beneficial to mitigate the crack potential in rib-to-deck PJP welds.]]></description>
      <pubDate>Fri, 30 Jan 2009 07:38:04 GMT</pubDate>
      <guid>https://trid.trb.org/View/878416</guid>
    </item>
    <item>
      <title>Synthesis Study: Heat Treatment and Its Effects on Rehabilitating Steel Bridges in Indiana</title>
      <link>https://trid.trb.org/View/864645</link>
      <description><![CDATA[The literature review of prior heat straightening research indicated that significant research has been conducted on the development of: (i) heat straightening repair techniques and their field implementation, (ii) guidelines and recommendations for heat straightening repair, (iii) empirical procedures for estimating plastic rotations achieved during heat straightening, (iv) empirical procedures for predicting residual stresses caused by heat straightening, and (v) the effects of heat straightening on the structural properties of repaired bridges. Currently, there is a need for additional research on: (a) the fatigue performance of heat straightened beams, (ii) the effects of single and multiple heat straightening on the fracture toughness and microstructure of steel beams, (iii) the development of guidelines for evaluating and replacing steel beams subjected to single or multiple damage-repairs, and (iv) investigating the effects of realistic heat straightening with imperfections on the properties and serviceability of steel beam bridges. The literature review of existing heat treatments indicates that heat straightening with maximum temperature limited to 1200°F is relatively similar to the process annealing heat treatment. Heat straightening with maximum temperature limited to 1400oF is similar to the normalizing annealing heat treatment. Both these heat treatments repair plastically deformed microstructure by the phenomenon known as recovery and recrystallization. Normalizing annealing is more efficient and faster than process annealing in repairing the plastically deformed microstructure by recrystallization. Heat treatment and repair of the material microstructure is incidental to the heat straightening repair process. The heat straightened beam can be further heat treated to complete the repair of the material microstructure (recrystallization etc.). The practical and economic feasibility of additional heat treatment using electrically powered and controlled radiant heaters was evaluated and found to be reasonable.]]></description>
      <pubDate>Tue, 22 Jul 2008 09:07:09 GMT</pubDate>
      <guid>https://trid.trb.org/View/864645</guid>
    </item>
    <item>
      <title>Heat-Straightening Repair of Damaged Steel Bridge Girders: Fatigue and Fracture Performance</title>
      <link>https://trid.trb.org/View/860743</link>
      <description><![CDATA[This report summarizes the results of a project to establish limits, based on fatigue and fracture performance, on the number of damage and repair cycles to which damaged steel bridge girders may be subjected using the heat-straightening procedure.  A key product presented here is suggested revisions to the Federal Highway Administration (FHWA) manual of practice for heat straightening.  The report will be of particular interest to engineers in state highway agencies and industry responsible for bridge maintenance and repair.]]></description>
      <pubDate>Fri, 13 Jun 2008 09:06:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/860743</guid>
    </item>
    <item>
      <title>Implementation of Heat-Straightening Repairs for Louisiana Bridges</title>
      <link>https://trid.trb.org/View/860292</link>
      <description><![CDATA[The goal of this study was to implement the latest heat-straightening repair technology on a Louisiana bridge.  The bridge chosen was an overpass just east of Lake Charles crossing I-10.  Working with both state and district personnel, the bridge was repaired during August 1998.  A facia noncomposite beam had been impacted and the bottom flange displaced 18 in. (0.45 m).  The repair was designed by the Louisiana State University team and implemented in conjunction with Louisiana Department of Transportation and Development personnel.  Described in this report are the design of the repair, the step-by-step implementation, and a discussion of lessons learned.  It is concluded that heat straightening is an effective alternative for repairing damaged steel bridges.]]></description>
      <pubDate>Wed, 04 Jun 2008 17:18:35 GMT</pubDate>
      <guid>https://trid.trb.org/View/860292</guid>
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