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    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <language>en-us</language>
    <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>Investigations of Toroidal Winding Doubly Salient Reluctance Machines With Sinusoidal Excitations</title>
      <link>https://trid.trb.org/View/2665517</link>
      <description><![CDATA[A novel three-phase doubly salient reluctance machine (DSRM) with both toroidal windings (TWs) and sinusoidal excitations are proposed and investigated. The machine topology and winding characteristics are introduced. The operating principle and torque production mechanism are elaborated in which the magnetic gearing effects are revealed. Moreover, the equivalent winding pole-pair is defined to facilitate the winding factor calculations, based on which the slot/pole number combination can be carefully selected to obtain the high amplitudes of effective winding magneto-motive forces (MMFs) and high torques. Moreover, the effects of critical design parameters are analyzed, and the machines are optimized. Based on theoretical and finite element (FE) analyses, the proposed DSRMs are evaluated and compared with the diverse DSRMs adopting either concentrated windings (CWs) or distributed windings (DWs). The results reveal that the proposed TWs not only contribute to higher torques than the CWs but also feature with shorter end-windings as well as lower copper losses than the DWs. The torque ripples are also alleviated. Finally, a DSRM prototype with TWs is manufactured and tested for validations.]]></description>
      <pubDate>Mon, 01 Jun 2026 09:13:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/2665517</guid>
    </item>
    <item>
      <title>Optimizing Resolver Excitation: A Rotary Transformer-Based Filter for Sinusoidal Wave Generation From Square-Wave Input</title>
      <link>https://trid.trb.org/View/2665451</link>
      <description><![CDATA[One key factor influencing the accuracy of resolver output is the type of sensor excitation waveform, which significantly impacts the computational load in the signal generation process. Historically, sinusoidal waveforms have been the ideal choice for feeding resolvers, as they yield the lowest output errors. However, generating high-frequency sine waves presents a challenge for resolver-to-digital converters (RDCs). This article addresses this challenge by using the rotary transformer (RT) of the brushless wound rotor (WR) resolver as a filter to provide sinusoidal excitation while reducing computational requirements. The stator of the RT is fed with a square wave, producing a sine wave on the rotor section to feed the resolver. The design process of an effective filter with the RT is detailed, and a model for evaluating and optimizing transformer performance is proposed. Afterward, the effect of varying the transformer’s electrical elements on filter performance is analyzed. Subsequently, a hybrid model for WR resolvers is presented, and the performance of the sensor with square-wave feeding and the designed filter is assessed. Finally, the sensor, along with the designed filter, is built and tested to validate the findings.]]></description>
      <pubDate>Tue, 26 May 2026 11:56:23 GMT</pubDate>
      <guid>https://trid.trb.org/View/2665451</guid>
    </item>
    <item>
      <title>Analyzing the Effectiveness and External Noise Levels of Sinusoidal and Traditional Shoulder Rumble Strips</title>
      <link>https://trid.trb.org/View/2646169</link>
      <description><![CDATA[Shoulder rumble strips provide an effective and low-cost safety measure to prevent roadway departure crashes. Despite their reported safety benefits, they generate external noise levels that often cause noise complaints from nearby residents. To address this challenge, this study conducted field measurements to evaluate the performance of newly constructed four sinusoidal and one traditional shoulder rumble strip designs. The objective of this study is to identify and evaluate the performance of promising designs that are capable of providing adequate in-vehicle noise levels while reducing their generated external noise levels. The field measurements were conducted using a passenger car following the American Association of State Highway and Transportation Officials Statistical Isolated Pass-by method and the Society of Automotive Engineers (SAE) standard for Measurement of Interior Sound Levels of Light Vehicles. The results of the field measurements show that all the tested sinusoidal designs generated lower external noise levels than the traditional rumble strip design while providing adequate in-vehicle noise level increases to alert inattentive drivers. The results also show that the two tested sinusoidal rumble strip designs with wavelengths of 30.5 cm (12 in.) and 40.6 cm (16 in.) provided adequate in-vehicle noise level increases while generating external noise level increases that are lower than 85% and 62% of previously tested designs, respectively. These results should be useful to State Departments of Transportation and enable them to utilize these original and effective designs, especially in residential areas, to lower the external noise levels generated by shoulder rumble strips while maintaining their roadway safety benefits.]]></description>
      <pubDate>Tue, 30 Dec 2025 08:56:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/2646169</guid>
    </item>
    <item>
      <title>Optimization of Nonsinusoidal Twisting Motion for Enhanced Aerodynamic Performance of Three-Dimensional Flapping Wings</title>
      <link>https://trid.trb.org/View/2628073</link>
      <description><![CDATA[The combined motion of flapping and twisting in a flapping wing can achieve high propulsion efficiency. However, prior research has predominantly concentrated on the analysis of 2D airfoils subjected to sinusoidal twisting motion. Nevertheless, the influence of nonsinusoidal motion patterns on the aerodynamic performance of 3D wings is significant, yet most studies focus on the hovering state without flow, with few extending to forward flight conditions. To obtain the optimal nonsinusoidal twisting motion pattern for 3D flapping wings, this paper designs a custom function based on the concept of piecewise functions and proposes an optimization framework based on surrogate models. The study finds that the optimal motion pattern results in a drag coefficient approximately 76.4% lower and a propulsion efficiency about 73.5% higher than that of the baseline motion pattern. Moreover, a simplified method for rapidly calculating the lift coefficient is introduced. It was discovered that the differences in twisting patterns lead to variations in the effective angle of attack and effective inflow velocity over time, which subsequently affect the generation and shedding of leading-edge vortices, resulting in a fundamental change in the mechanisms of aerodynamic force generation. In comparison to wings following sinusoidal motion patterns, wings following a square wavelike motion pattern, characterized by prolonged periods of large twisting angles and brief rapid twists, demonstrate a drag coefficient reduction of approximately 34.2% and an increase in propulsion efficiency of about 45.2%.]]></description>
      <pubDate>Mon, 22 Dec 2025 17:03:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/2628073</guid>
    </item>
    <item>
      <title>Chebyshev polynomials based compensator design via higher order sinusoidal input describing functions in traction motor drive to improve performance of electric vehicle</title>
      <link>https://trid.trb.org/View/2443563</link>
      <description><![CDATA[In electric vehicles (EVs), the efficient selection of the basic elements and the control of the electric motor and the overall system is vital to extend the performance of the vehicle. A feedback control loop with proportional-integral (PI) controllers is usually used in the control of electric motors. Within the scope of this study, the system is handled with frequency-based methods and it is aimed to reduce the performance degrading effect on the system output. In this study, Higher Order Sinusoidal Input Describing Functions (HOSIDFs) are used in order to improve the performance of EVs. Here, the EV is modeled as a Lur’e-type system and a compensator is designed within the PI speed control loop of the electric motor by using Chebyshev polynomials. The optimal coefficients of the Chebyshev polynomials-based compensator minimize the cost function which is related to the harmonics of the system output. This work introduces a novel approach for controlling the traction motor of EVs using a frequency-based method through HOSIDFs. The objective is to enhance the performance of the drive system. Throughout this study, it is also aimed to improve the consumption of the battery and passenger comfort. The results and success of the proposed method are illustrated in time-domain and harmonic plots.]]></description>
      <pubDate>Fri, 25 Oct 2024 14:02:48 GMT</pubDate>
      <guid>https://trid.trb.org/View/2443563</guid>
    </item>
    <item>
      <title>Evaluation of Sinusoidal Rumble Strips on Noise Mitigation and Bicycle Accommodation</title>
      <link>https://trid.trb.org/View/2389997</link>
      <description><![CDATA[Lane departure crashes are among the most common crashes in Florida and in the United States. Many departments of transportation (DOTs) prioritize reducing both the frequency and severity of these accidents. Auditory vibratory treatments (AVTs), or rumble strips, are frequently used to prevent or reduce lane departure incidents. Traditional rumble strips produce exterior noises that become a burden to nearby residents. To address the noise issues, several DOTs considered a new type of AVT called sinusoidal rumble strips. The research team conducted an in-depth literature review, agency interviews, a focus group, and an assessment of studies conducted by the Florida Department of Transportation (FDOT) to evaluate the noise reduction and bicycle accommodation of sinusoidal rumble strips installed in Florida and across the nation. The research concludes that sinusoidal rumble strips can effectively mitigate external noise problems while effectively notifying drivers and occupants of lane departures.]]></description>
      <pubDate>Thu, 22 Aug 2024 15:11:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/2389997</guid>
    </item>
    <item>
      <title>Spectrum-Based Method for Fatigue Damage under Excitation of Sinusoidal Sweeps for Automotive Systems</title>
      <link>https://trid.trb.org/View/2367677</link>
      <description><![CDATA[Vibration from a mechanical system not only produces unwanted noises annoying to people around, but also runs a risk of fatigue failure that would actually hinder its functionality. There are several forms of vibration depending on the sources of excitation forms. Mechanical systems with rotating components can be subjected to sinusoidal excitation due to the fact the center of mass is not perfectly aligned with the rotating axis. If the rotating speed is strictly ramping up or ramping down, this can create an excitation whose frequency is changing with time in a frequency range corresponding to the speeds swept. Compared with a single sinusoidal excitation, the issue with fatigue at swept sinusoidal excitation, is that as it sweeps through a wide frequency range, some swept frequencies will definitely coincide with the natural frequencies of the system. Certainly, the stress response exactly at the resonant frequency becomes the highest and could account for a lot of fatigue damage. However, the stress in the vicinity of that resonance frequency could also contribute to the accumulated damage, depending on how long the system is exposed to the vibration there. Hence, only using the stress magnitude at the resonance to evaluate the durability is not adequate. The purpose of this work is to present a spectrum-based approach to calculate the cumulative fatigue damage as the stress is oscillating around its means with gradually increased or decreased frequency. The fatigue prediction is based on the stress spectrum obtained from a steady-state solution to a linear vibration system at each individual frequency. The fatigue damage spectrum is derived from the stress spectrum, along with a sweeping mode for the excitation frequency. Two of the commonly-used sweep modes (i.e. logarithmic and linear sweeping modes) are studied for an automotive component and their difference in the effect on the damage results are discussed in detail, through an example of an automotive component. In this work, it will be demonstrated how to choose sine sweeping rate such that the steady-state solution is guaranteed and the premise of this spectral method for fatigue is still valid.]]></description>
      <pubDate>Mon, 10 Jun 2024 08:43:18 GMT</pubDate>
      <guid>https://trid.trb.org/View/2367677</guid>
    </item>
    <item>
      <title>Sinusoidal Rumble Strips Safety Evaluation</title>
      <link>https://trid.trb.org/View/2309154</link>
      <description><![CDATA[This evaluation determined the change in crash frequency, type or severity associated with longitudinal sinusoidal rumble strips on rural two-lane undivided Minnesota roadways constructed between 2018 and 2022. Crash modification factors (CMFs) were estimated using cross-sectional analysis to compare crash experience of locations with sinusoidal rumble strips (i.e., centerline only, centerline and shoulder, or shoulder only) compared to roads with rectangular rumble strips. The cross-sectional analysis matched sites with sinusoidal and rectangular rumble strips using matched-pair comparisons. Negative binomial (NB) or Poisson log-linear regression models were used to model the crashes at all treatment and non-treatment sites. There was a total of approximately 327 miles of treated (i.e., centerline only, centerline and shoulder, or shoulder only sinusoidal rumble strips) and approximately 302 miles of untreated (i.e., centerline only, centerline and shoulder, or shoulder only rectangular rumble strips) on rural two-lane divided roads. Overall, the results of the models indicated no significant differences in crash rates between rural two-lane undivided roads with sinusoidal rumble strips, and rural two-lane undivided roads with rectangular rumble strips.]]></description>
      <pubDate>Wed, 24 Jan 2024 16:55:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/2309154</guid>
    </item>
    <item>
      <title>Numerical investigation of the effects of continuous and non-continuous SSLEs on hydrofoils at different AoAs and their impact on the stall angle</title>
      <link>https://trid.trb.org/View/2215904</link>
      <description><![CDATA[In the current paper, a particular leading-edge form called Step-Shaped Leading-Edge (SSLE) is studied in continuous and non-continuous forms along the span of an infinite wing based on , via the RANSE scheme. The computed lift and drag coefficients are in good agreement with experimental data up to an angle of attack of , i.e. the stall angle of the baseline model. This study shows that although the continuous SSLE lowers the stall angle at 12, the non-continuous SSLE increases it up to . The flow visualisation over the studied models has clearly illustrated how the SSLE alter the flow pattern over a hydrofoil. The model with non-continuous SSLE has lift and drag coefficient diagrams similar and even better in some angles of attack than hydrofoils with sinusoidal leading edge. Furthermore, to bring order into the chaos and score different leading-edge forms, a quantitative and visualising rating technique is proposed.]]></description>
      <pubDate>Mon, 31 Jul 2023 08:45:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/2215904</guid>
    </item>
    <item>
      <title>In-plane crushing of a novel sinusoid-curved honeycomb under static and dynamic loadings</title>
      <link>https://trid.trb.org/View/2189300</link>
      <description><![CDATA[The in-plane crushing response of a novel honeycomb consisting of sinusoid-curved ligaments is comparatively analyzed under quasi-static and dynamic loadings using numerical and theoretical methods. The finite element models for ABAQUS/Explicit are validated against the experimental results obtained from the quasi-static tests on the additively manufactured translational-sinusoid honeycomb (TSH) and symmetrical-sinusoid honeycomb (SSH). Quantitatively, the effect of impact velocity and relative density on the deformation mode is revealed by summarizing the deformation maps of SSH and TSH. It implies that the critical velocities at which the transformation of deformation mode happens are larger for SSH than those for TSH. Cells of TSH prefer to be tightly stacked together due to the chirality-liked configuration, whereas the symmetrical configuration strengthens the buckling resistance of SSH cells and the provisional and full densification states would sequentially experience in the crushing process. Investigation on the crushing performance further revealed that the crushing strength and the energy absorption capacity of SSH are slightly higher than those of TSH. In contrast, the densification strain of TSH is larger than that of SSH for a wide range of impact velocity. Regarding the deformation mechanism of representative units, theoretical models are proposed to evaluate the crushing strength of the sinusoid-curved honeycombs. Good agreement between theoretical predictions and numerical results is obtained under both quasi-static and dynamic loadings. Moreover, the effect of the cell topology on the mechanical performance of sinusoidal-curved honeycomb is discussed.]]></description>
      <pubDate>Mon, 12 Jun 2023 09:13:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/2189300</guid>
    </item>
    <item>
      <title>Real-time online intelligent perception of time-varying cable force based on vibration monitoring</title>
      <link>https://trid.trb.org/View/2024997</link>
      <description><![CDATA[During the service period of cables, the corrosion fatigue is the principal damage form under the combined action of traffic loading and external environment. The real-time and accurate perception of the time-varying cable force in service is the foundation for exactly evaluating the safety status of cable. However, most of the existing methods identifying cable force can only obtain the average cable force over a period of time, besides, although a few methods can detect the time-varying cable force, they cannot meet the requirements of time-frequency resolution. This paper proposes a real-time intelligent vibration-based perception method of the time-varying cable force based on the block recursive APES method and cable dynamic stiffness analysis theory. Through the efficient recursive APES method, the real-time intelligent perception of time-varying frequencies is abstracted from the real-time monitoring vibration signal of the cable. Based on the accurate dynamic analysis model of the cable, the cable forces and modal frequencies calculated by the theoretical formula are fitted to obtain an accurate identification method for the time-varying cable force, which can meet the real-time and accuracy requirements at the same time. Combining the above two methods, a real-time intelligent perception method for perceiving the time-varying cable force is proposed. In order to verify the feasibility and accuracy of the proposed method, cases on real bridge cables were analyzed, and the selection methods of order, range and accuracy of time-varying frequency and cable force were proposed. The results demonstrated that the proposed method can realize the real-time accurate perception of time-varying cable force, and the temperature effect has an obvious influence on the time-varying cable force. In the statistical analysis of cable stress amplitude, the influence of temperature trend should be removed.]]></description>
      <pubDate>Thu, 17 Nov 2022 10:15:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/2024997</guid>
    </item>
    <item>
      <title>SPR-4739:  Sinusoidal Rumble Strips Measures of Effectiveness</title>
      <link>https://trid.trb.org/View/2026877</link>
      <description><![CDATA[This project will estimate and compare the safety performance of conventional and sinusoidal rumble strips to inform INDOT’s decision of rumble strip design. Edge-line rumble stripes narrower than standard 12” will be checked for safety and warning effectiveness to accommodate pedestrians and bicyclists within existing road shoulders together with stripes.  Crash Modification Factors will be estimated for several types of crashes at three levels of crash severity to help select alternative safety countermeasures including rumble stripes lateral location: centerline only, shoulder only, and centerline plus shoulder.]]></description>
      <pubDate>Wed, 21 Sep 2022 14:29:36 GMT</pubDate>
      <guid>https://trid.trb.org/View/2026877</guid>
    </item>
    <item>
      <title>Event-Based Sampling for Handwheel Vibration Analysis</title>
      <link>https://trid.trb.org/View/1797547</link>
      <description><![CDATA[Over the past 20 years automobile quality, and consumer perceptions thereof, have been an increasing part of the vehicle engineering process. In automotive systems, torque-induced handwheel vibration is a significant source of consumer annoyance.         When dealing with torque recordings containing a single or very small number of sinusoids, a time-referenced signal can easily be manipulated to yield instantaneous torque estimates. As the number of sinusoids (orders) grows, however, this becomes more difficult.         In this paper, the authors demonstrate a simple technique to effectively estimate instantaneous torque level of high-order torque components when there are many higher-order sinusoids. The point is made that basic signal processing techniques applicable to time-referenced signals are also applicable to those referenced to angle or other variables.]]></description>
      <pubDate>Wed, 23 Feb 2022 16:16:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/1797547</guid>
    </item>
    <item>
      <title>Perceived discomfort for typical helicopter vertical sine vibrations for seated participants</title>
      <link>https://trid.trb.org/View/1883157</link>
      <description><![CDATA[Vibrations contribute to helicopter’s ride comfort. This study aimed to determine the relationship between main rotor vertical excitations and discomfort. Fifty-three participants, seated on a helicopter seat fixed to a vibration test bench, evaluated the discomfort of vertical sinusoidal vibrations using a magnitude estimation procedure. Stimuli had a frequency between 15 and 30 Hz and a level between 0.32 and 3.16 m/s². The average discomfort was shown related to vibration velocity using Steven’s power law, without any frequency dependence. The exponent depended on velocity and was 1.18 for higher velocities (approx. above 0.008 m/s) and 0.65 for velocities below that limit.]]></description>
      <pubDate>Thu, 16 Dec 2021 16:08:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/1883157</guid>
    </item>
    <item>
      <title>Modeling Synchronous and Induction Machine with Wireless Rotor</title>
      <link>https://trid.trb.org/View/1847321</link>
      <description><![CDATA[The new wireless rotor electrical machine has all the coils placed on the stator. The laminated wireless rotor serves as a magnetic field switcher. A wireless rotor is cold, and it facilitates machine cooling. The model of the wireless rotor machine includes electrical and mechanical components. The wireless rotor machines can find an application in practice because they have advantages over existing devices. In modeling, the authors use a new approach. The authors consider a motor as a natural control system with torque feedback. Such an approach simplifies analyses and adjustment of the operation of an electrical machine. First, the authors analyze an open-loop control system without torque feedback. In this case, by changing the rotor speed under external torque, the authors can receive the torque-speed motor characteristics. After some adjustments to the open-loop system, the authors can consider the close loop control system with torque feedback. The authors use a space vector representation for sinusoidal electric components. Such a description allows the use of sinusoidal components in transient conditions. For modeling, the authors use the graphical programming language, Simulink. The Graphical language allows showing the physical interpretation of the operation of a wireless rotor machine. The transient and steady-state results of modeling electrical and mechanical components are natural and visible at any point in the Simulink model. It facilitates the analysis results of the simulation. This modeling will find applications for designing the static and dynamic properties of the wireless rotor machines. The results can be useful for analyses and create regular AC machines.]]></description>
      <pubDate>Fri, 30 Jul 2021 17:50:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/1847321</guid>
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