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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" />
    <description></description>
    <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>
    </image>
    <item>
      <title>Prediction of Dynamic Stiffness of Automotive Components Using
                    Support Vector Methods</title>
      <link>https://trid.trb.org/View/2675966</link>
      <description><![CDATA[In the current scenario of EV revolution in the automotive industry, NVH                     performance of the vehicles is one of the major points of sale to the customers.                     Auxiliary components play one of the predominant roles in the contribution of                     noise to overall vehicle interior or exterior sound pressure levels, which                     impact customer vehicle comfort. CAE prediction of NVH performance of automotive                     components involves a lot of design iterative processes, large server space                     utilization, and time-consuming.To reduce cost and time, data-driven technologies like AI algorithms can help CAE                     engineers because of their high efficiency and high precision. In the current                     research, a wiper motor mount stiffness prediction algorithm was designed based                     on the historical data using CAE analysis and AI algorithms, and improved                     prediction accuracy by tuning the parameters of AI algorithms using grid search                     methodology.High prediction accuracy of wiper motor mount stiffness has been achieved with                     the method of support vector machine. CAE engineers can avoid iterative                     processes by utilizing the optimized design parameters from the prediction                     results without running full finite element analysis simulations.]]></description>
      <pubDate>Mon, 02 Mar 2026 15:16:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/2675966</guid>
    </item>
    <item>
      <title>Rear Wiper Motor with Nozzle Integration</title>
      <link>https://trid.trb.org/View/2663416</link>
      <description><![CDATA[In today's dynamic driving environments, reliable rear wiping functionality is essential for maintaining safe rearward visibility. This study sharing the next-generation rear wiper motor assembly that seamlessly integrates the washer nozzle, delivering improved performance alongside key benefits such as better Buzz, Squeak, and Rattle (BSR) characteristics, reduced system complexity, cost savings, and enhanced perceived quality. This integrated design simplifies the hose routing which improves the compactness and the efficiency of the design. This also enhances the spray coverage and minimizes the dry wiping unlike the traditional systems that position the washer nozzle separately.A non-return valve (NRV) is incorporated to eliminate spray delays ass it maintains consistent water flow giving cleaning effectiveness. Since this makes the nonfunctional parts completely leak proof due to the advanced sealing, it increases the durability and reliability in long run. As this proposal offers a sustainable solution, it can be considered as the new benchmark in rear wiper technology.]]></description>
      <pubDate>Mon, 02 Feb 2026 16:36:55 GMT</pubDate>
      <guid>https://trid.trb.org/View/2663416</guid>
    </item>
    <item>
      <title>CFD Methods for Prediction of Washer Fluid Behavior During Wiper Operation</title>
      <link>https://trid.trb.org/View/2592147</link>
      <description><![CDATA[When wipers are operated while driving, washer fluid flows over side windows, affecting the driver's visibility. To predict this phenomenon, this study introduces a CFD method for analyzing airflow and washer fluid behavior using the Lattice Boltzmann method and the Lagrangian particle tracking. The wind tunnel test validated this method, showing consistent results with the experiment, including the washer fluid spread from the upper to the center of the A-pillar and the position of the washer fluid reaching the side window. This method allows for early-stage design improvements in vehicle performance related to washer fluid, even without an actual vehicle.]]></description>
      <pubDate>Thu, 30 Oct 2025 13:26:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/2592147</guid>
    </item>
    <item>
      <title>Vibration response analysis of boneless wiper-windshield system based on multi-body dynamics model</title>
      <link>https://trid.trb.org/View/2570789</link>
      <description><![CDATA[The vibration and noise generated by the boneless wiper-windshield system during its actual operation bother the occupants. Exploring the dynamic characteristics of the boneless wiper-windshield system is a prerequisite for understanding vibration and noise. In this paper, the dynamic characteristics of the boneless wiper-windshield system are investigated, and a rigid-flexible coupled multi-body dynamic model matching the real boneless wiper-windshield system is constructed. The friction characteristic of the dynamic model is studied through the wiper test bench experiment. The nonlinear dynamic response of the dynamic model is calculated with the Adams and results of the frictional vibration are well reproduced in real motions. The parallel analysis of the simulation calculation results and the real vehicle test results confirms the validity of the model. The results show that the vibration generation mechanism at the moments before and after the reversal can be explained by the instability of the wiper blades due to the negative friction characteristic. There are differences in the magnitude of the reversal impact force and the moment of reversal at each position of the wiper blade. The effect of the speed-gears on the system vibration is analyzed through the simulation results. The analysis method and simulation results in this article can provide reference for the research on vibration and noise control of boneless wiper systems.]]></description>
      <pubDate>Fri, 18 Jul 2025 09:05:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/2570789</guid>
    </item>
    <item>
      <title>Correlated Beamforming Based on Deconvolution Methods for Identified Vehicle Exterior Wind Noise Sources and Interior Noise</title>
      <link>https://trid.trb.org/View/2552111</link>
      <description><![CDATA[Sound source identification based on beamforming is widely used today as a spatial sound field visualization technology in wind tunnel experiments for vehicle development. However, the conventional beamforming technique has its inherent limitation, such as bad spatial resolution at the low frequency range, and limited system dynamic range. To improve the performance, three deconvolution methods CLEAN, CLEAN-SC and DAMAS were investigated and applied to identify wind noise sources on a production car in this paper. After analysis of vehicle exterior wind noise sources distribution, correlation analysis between identified exterior noise sources and interior noise were conducted to study their energy contribution to vehicle interior. The results show that the algorithm CLEAN-SC based on spatial source coherence shows the best capability to remove the sidelobes for the uncorrelated wind noise sources, while CLEAN and DAMAS, which are based on point spread functions have definite limitations.Considering the testing car, the main noise source of exterior is from the wheelhouse region, then follows the rearview mirror with much lower sound energy. However, noise from the mirror contributes most to the vehicle interior, while the contribution from wheelhouse region ranks the second place. In addition, windshield wipers and door handle can do perceptible contributions to vehicle interior noise at some characteristic frequency bands.]]></description>
      <pubDate>Tue, 13 May 2025 10:11:05 GMT</pubDate>
      <guid>https://trid.trb.org/View/2552111</guid>
    </item>
    <item>
      <title>The influence of contact distribution shaping on the dynamic response of a wiper blade</title>
      <link>https://trid.trb.org/View/2437562</link>
      <description><![CDATA[The primary function of windscreen wipers is to remove water and debris from the windscreen, ensuring the driver has a clear view of the road ahead. Predicting wiper performance at the design stage is therefore important to ensure their safe operation. There is hence a need to develop physics-based models of wiper performance that can be used as evaluative tools early in the design stage. This paper presents an analysis of the impact of changing screen curvature on the contact force distribution of a wiper blade and the subsequent effects on the transient dynamics. The contact distributions for three distinct screen curvatures and three loading points are calculated via FEA (finite element analysis) and subsequently analysed via multiple connected mass spring dampers to model the wiper blade lip transient dynamics. By analysing time and frequency domain data for several calculated contact distributions it is found that decreasing the screen curvature reduces the contact force at the centre of the blade, however, increases the amplitude of vibrations and range of frequencies observed. Additionally, it is found that moving the loading point towards the tip of the blade reduces the amplitude of vibrations, a result analogous to that of increasing the screen curvature. Based upon the understanding gained through this work the influence of design criteria on wiper blades can now be assessed, and several suggestions made as to how to reduce windscreen wiper noise.]]></description>
      <pubDate>Wed, 23 Oct 2024 11:45:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/2437562</guid>
    </item>
    <item>
      <title>Can pedestrian headform test results reflect the distribution of head injuries in the real world?</title>
      <link>https://trid.trb.org/View/2367480</link>
      <description><![CDATA[Wrap around distance (WAD) is an important index to evaluate the contact position between pedestrian head and vehicle, and is also one of the key parameters of pedestrian accident reconstruction. The purpose of this paper is to explore whether the pedestrian headform testcan reflect the distribution of head injury in the real world. Firstly, in order to study the distribution of pedestrian head WAD in road accidents in China, a head WAD prediction model was established using logistic regression based on pedestrian height and vehicle collision speed. Secondly, in order to study the distribution of the risk of severe head injuries among pedestrians in accidents, the frequency of pedestrian head impact and the proportion of pedestrian head injury were counted respectively for sedans and SUVs. Subsequently, a risk curve for severe head injuries was constructed based on the head impact frequency and the proportion of severe injuries, utilizing a method that incorporates joint probability. Finally, to investigate the relationship between the headform test results and the distribution of severe head injury risks among pedestrians in road traffic accidents in China, a meticulous regional division of the head WAD was conducted based on the vehicle's front structure. A qualitative comparison was made between the distribution of headform test results in that area and the distribution of pedestrian injuries in the real world within that specific region. The results indicate that the location of pedestrian head impacts is primarily concentrated within the range of WAD 1500 mm to WAD 2300 mm. When pedestrians collide with sedans, the peak frequency of head impact occurs at WAD 1900 mm, whereas in collisions with SUVs, this peak occurs at WAD 1700 mm. In the areas of sedan windshields and A-pillars, as well as the rear portion of SUV hoods and windshield wiper regions, pedestrians' heads are most susceptible to severe injuries. It is noteworthy that within the WAD1000-WAD1500 mm range, the risk of severe head injuries for pedestrians is nearly zero. This study, through the analysis of severe head injury distribution among pedestrians in China, assessed the effectiveness and applicability of The China Insurance Automotive Safety Index (C-IASI) headform test. It provides targeted recommendations for the enhancement of the C-IASI pedestrian assessment protocol and offers crucial reference for optimizing the design of vehicle front structures.]]></description>
      <pubDate>Tue, 16 Apr 2024 09:52:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/2367480</guid>
    </item>
    <item>
      <title>Physical Testing Methodology and Evaluating Windscreen Wiping with Respect to Vision Zones for Vehicle Category other than M1</title>
      <link>https://trid.trb.org/View/2335017</link>
      <description><![CDATA[The windscreen wiping system is mandatory requirement for automotive vehicle as per Central motor vehicle rules (CMVR). The main scope of the standard is to ensure vision zones to be wiped by wiping system to ensure maximum field of vision to the driver. The evaluation of vision zones as per IS 15802:2008 is generally determined by virtual simulation by OEMs. The limitation of virtual simulation is due to actual tolerances in vehicle, due to seat fitment, ergonomic dimensions, seat cushioning effect and wiper non-effective operation which are not taken into consideration very well off. The testing methodology described in the paper is an in-house developed test method based on SAE recommended practices. With the help of 3D H-point machine and a laser based ‘Theodolite’ equipped with horizontal and vertical angle projections from single pivot point is used to develop various vision zones on an actual vehicle windscreen as per technical data. These zones are later compared with wiped area to evaluate field of vision. The standard is applicable to vehicle other than M1 category viz M2, M3, N1, N2 and N3. Critical vehicle parameters such as SgRP (seating reference point), seat back angle and AHP (accelerator heel point), seat travel, GVW (gross vehicle weight) and category of the vehicle are required.The paper clearly describes calculation steps for calculating Automotive tool reference line, equation for Eye ellipse, placing eye ellipsoide centroid coordinates with respect to VCS (vehicle coordinate system) in vehicle ecosystem, projecting Ellipse tangents for distinct vision zones and evaluating mandatory standard requirement of percentage of wiped area with respect to vision zones at vehicle level. The work scope in this paper will enable manufactures to validate the virtual simulation results with respect to actual vehicle considering all tolerances. This test method can be adapted widely to evaluate more precise test results and data for field of vision certification activity.]]></description>
      <pubDate>Wed, 07 Feb 2024 11:27:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/2335017</guid>
    </item>
    <item>
      <title>Applications of Neural Networks to Metallic Flexor Geometry
                    Optimization of Flat Wipers</title>
      <link>https://trid.trb.org/View/2259876</link>
      <description><![CDATA[
                
                In recent years, demands of flat wipers have rapidly increased in the vehicle
                    industry due to their simpler structure compared to the conventional wipers.
                    Procedures for evaluating the appropriate metallic flexor geometry, which is one
                    of the major components of the flat wiper, were proposed in the authors’
                    previous study. However, the computational cost of the aforementioned procedures
                    seems to be unaffordable to the industry. The discrete Winkler model regarding
                    the flexor as the Euler–Bernoulli beam is established as the mathematical model
                    in this study to simulate a flexor compressed against a surface at various
                    wiping angles. The deflection of the beam is solved using a finite difference
                    method, and the calculated contact pressure distributions agree fairly with
                    those based on the corresponding finite element model. Flexor designs are paired
                    with various windshield surfaces to accumulate a sufficiently large simulation
                    database based on the mathematical model. An artificial neural network (ANN)
                    approach is developed to predict contact pressure distributions of the flexor
                    much faster than the mathematical model. Geometry of the curved surface is
                    represented by a shape code obtained via a principal component analysis (PCA)
                    and used in the ANN model. The ANN algorithm is also applied to efficiently
                    evaluate the wiping patterns according to the simulated contact pressure
                    distributions. These patterns are then classified by using a convolutional
                    neural network (CNN) to identify several suitable flexor designs for the
                    specific windshield. The flat wiper suggested by the current procedures is
                    experimentally validated to justify its qualified wiping performances.
            ]]></description>
      <pubDate>Tue, 03 Oct 2023 15:42:19 GMT</pubDate>
      <guid>https://trid.trb.org/View/2259876</guid>
    </item>
    <item>
      <title>A theoretical analysis of friction and vibration characteristics of wiper reversal process</title>
      <link>https://trid.trb.org/View/2166420</link>
      <description><![CDATA[This paper is concerned with the friction and vibration characteristics of a vehicle wiper-windscreen contact. The dynamics and friction models of the wiper-windscreen system are established to study the frictional vibration and noise of the wiper-windscreen system. The dynamic model of the wiper-windscreen system is established and the analytical formulas are derived. Based on the negative slope formula of friction coefficient with respect to relative velocity, the Coulomb’s friction law, and the fluid lubrication characteristics, the friction models of the system are built in dry and wet operating conditions, respectively. Meanwhile, the formulas of friction coefficient and relative velocity in time domain are presented. The changes of blade angle and friction with time in different working conditions are investigated. The Runge-Kutta method is used to analyze the nonlinear dynamic response and friction characteristics of the friction models. The simulations successfully reproduce the vibrations of the wiper blade in actual motion. The effectiveness of the dynamic model and the friction models is verified by comparing the simulation results under different working conditions. The dynamics and friction models presented in this paper can provide theoretical references for structural optimization of the wiper blade, and thereby the vibration and noise control of the wiper-windscreen system.]]></description>
      <pubDate>Tue, 23 May 2023 10:09:11 GMT</pubDate>
      <guid>https://trid.trb.org/View/2166420</guid>
    </item>
    <item>
      <title>Virtual Methods for Water Management in Automotive Structures</title>
      <link>https://trid.trb.org/View/2173360</link>
      <description><![CDATA[The requirements of the automotive industry move along due to product competitiveness and this contributes to increase complexity in the requirements for evaluation. Simulation tools play a key role thanks to their versatility and multiple physical phenomena that can be represented.The axis of analysis for this paper is the problem of the interaction of airflow and water flow in the cowl/plenum/leaf screen components. Airflow is represented by HVAC system operating and water flow by the vehicle in torrential rain.Initially, one simulation is evaluated at a time, in one side, the airflow entering the HVAC system in which the amount of air entering is monitored and pressure drop, on the other, the water simulation on the vehicle, both using a Lagrangian CFD model (using with tools such as STAR CCM+® or Ansys Fluent®)Due to this, a CFD methodology was developed to evaluate the interaction of air and water flow. This uses CFD Eulerian model for airflow and a Lagrangian model for water, in which results from the initial simulation are included to evaluate the interaction of both fluids and consequently obtain a more significant result for water particle behavior.The research results show a significant change in the amount of water distribution in the system when it has airflow as an initial boundary condition.Furthermore, the kinematics of the windshield wipers is another key factor in the study, and it changes the physics of this analysis, which is currently under development to provide more effective results.]]></description>
      <pubDate>Tue, 16 May 2023 11:46:52 GMT</pubDate>
      <guid>https://trid.trb.org/View/2173360</guid>
    </item>
    <item>
      <title>Application of Sound Intensity to the Measurement of Aeroacoustic Noise Sources in Flow</title>
      <link>https://trid.trb.org/View/2173451</link>
      <description><![CDATA[In the late 1970’s and early 1980’s, Jing-Yau Chung along with Joseph Pope published several external General Motors reports on the then novel measurement of sound intensity (SI) using the two-microphone, cross-spectral method. Application of this measurement method was then extended to sound intensity measurements in flow. Through component wind tunnel measurements, it was determined that the intensity of noise sources could be accurately measured up to a level of 15 dB below the sound pressure level generated by flow noise on microphones. An initial application of this method was to the identification of noise sources alongside rolling truck tires. It was then extended to the measurement of the aerodynamic noise generated by protrusions added to automotive vehicle designs. These included items such as outside rearview mirrors, windshield wipers, A-pillar offsets, grille whistles, roof racks, underbodies, and fixed-mast radio antennas. Many of these could be applied on the early full-size clay models or other mock-ups as well as actual vehicles. An application of sound intensity was the development of the straked antenna design leading to a GM Defensive Patent and its now universal application to virtually all vehicles with simple fixed-mast antennas. The development of this design is highlighted along with the background on the application of sound intensity to measurements in air flow.]]></description>
      <pubDate>Tue, 16 May 2023 11:44:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/2173451</guid>
    </item>
    <item>
      <title>Quantitative Multi-Physics Tools for Automotive Wiper Design</title>
      <link>https://trid.trb.org/View/2166159</link>
      <description><![CDATA[The primary function of automotive windscreen wipers is to remove excess water and debris to secure a clear view for the driver. Their successful operation is imperative to vehicle occupants’ safety. To avoid reliance on experimental testing there is a need to develop physics-based models that can quantify the effects of design-based decisions on automotive wipers. This work presents a suite of evaluative tools that can provide quantitative data on the effects of design decisions. We analyse the complex non-linear contact interaction between the wiper blade and the automotive screen using finite element analysis, assessing the impact of blade geometry on the contact distribution. The influence of the evolution of normal applied load by the wiper arm is also investigated as to how it impacts the contact distribution evolution. The dynamics of the blade are subsequently analysed using a multiple connected mass spring damper system. Additionally, we apply hydrodynamic lubrication theory to study the residual film thickness post wipe and assess the effect of wiper blade geometry and lubricant composition. Finally, the complete wiper system is studied using a lump dynamic model, and bifurcation analysis is applied to determine areas of instability due to friction induced vibrations. Additionally, the wiper dynamics modelling shows peak frequencies occurring at 30-50Hz, which agrees well with a documented range of chatter frequencies. The friction coefficients calculated within the hydrodynamic model fall within experimentally documented ranges of lubricated sliding friction, µ ˜ 0.1. Furthermore, the areas of operational stability predicted by our bifurcation model coincide with current experimentally determined optimal operational regions for automotive wipers.]]></description>
      <pubDate>Mon, 01 May 2023 15:55:44 GMT</pubDate>
      <guid>https://trid.trb.org/View/2166159</guid>
    </item>
    <item>
      <title>Nonlinear Friction Compensation of Automotive Wiper Systems by Integral Control with Sign Reversal</title>
      <link>https://trid.trb.org/View/2104514</link>
      <description><![CDATA[In automotive wiper systems, nonlinear friction between the blade rubber and the windshield disturbs smooth motion, which causes tracking errors and increases operational noise. This paper proposes simple friction compensation based on linear feedback control with sign reversal of an integration. In simulation and experiment with a linkless wiper, the proposed method compensates for the nonlinear friction of the wiper motor and the blade rubber, and reduces the tracking error in particular for the slow motion after the wiper motion reverses.]]></description>
      <pubDate>Thu, 23 Mar 2023 10:20:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/2104514</guid>
    </item>
    <item>
      <title>Windshield Wiper System Design Integration</title>
      <link>https://trid.trb.org/View/1822664</link>
      <description><![CDATA[This paper presents development work on the design and analysis of the windshield wiper system. Three design categories are presented: geometrical design, wiper module and motor kinetics, and snow block structural analysis method. A comprehensive structural analysis method is outlined to determine the wiper system capability for continuous operation under a snow blocked condition. By using this design and analysis method, a robust windshield wiper system will be achieved.]]></description>
      <pubDate>Mon, 03 Oct 2022 16:08:40 GMT</pubDate>
      <guid>https://trid.trb.org/View/1822664</guid>
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