Assessment of acoustic pollution of areas bordering highways

The work is devoted to the peculiarities of acoustic pollution of roadside territories. The studied territory is characterized by uneven acoustic load on the experimental sections of the highways of the Republic of Crimea, which is associated with the peculiarities of traffic flow and technical characteristics of cars. The article considers the indicators of the equivalent and maximum levels of motor vehicle noise. As the research result, the excess of noise level from 10 to 30 dBA was revealed. The maximum level of acoustic pollution was recorded in 10-meter zone, at a distance of 30 m from the noise source the level of acoustic pollution is reduced to 5-10 dBA.

Door sealing mechanism and process in vehicle engineering

The reliability of door sealing plays an important role in maintaining the quality of vehicle noise, vibration, and harshness (NVH). To improve the reliability of door sealing, a novel sealing process has been proposed. The factors influencing the door sealing quality have been investigated. The relationships between the peeling force, peeling speed, and peeling time have been calculated using the five-variable rheological theory. The maximum stress versus time curve and the distribution of stress and strain at the moment of debonding have been obtained by nonlinear solid cohesive coupling dynamics simulation. The rolling process of the door sealing strip has been developed, and automatic rolling equipment for door sealing has been designed and manufactured. The factors influencing the peeling force have been determined by a peeling test of the door sealing strip. The results show that the peeling force increases with an increase in the peeling speed and time. The C-shaped structure at the front end of the base material during the stripping process makes the peeling angle sharp. In addition, the uneven stripping speed causes the stripping line to become irregular. The peeling force increases with the increase in rolling pressure and failure time. The optimum rolling pressure was 70 N/m2 and the optimum aging time was 24 h.

Field Measurement Analysis and Control Measures Evaluation of Metro Vehicle Noise Caused by Rail Corrugation

The noise caused by rail corrugation seriously affects the operation quality of metro vehicles. In this work, the rail corrugation, interior noise and wheel–rail noise of a metro line were tested, and the test results were compared with those after two kinds of treatments. The results show that rail corrugation is the main cause of the abnormal interior noise. The interior noise in many sections exceeds the limit, where clear rail corrugations from 31.5~63 mm are found. When the train passes through the rail corrugation section, the interior noise shows a clear increase, and the maximum increase is higher than 25 dB(A). After increasing the lateral stiffness of the track and rail grinding, the interior noise is reduced by 11.4 dB(A). After a long renovation time, the interior noise is effectively equal to that when the renovation was completed. The research results of this work can provide a reference for rail corrugation treatment and noise control.

Research on the Detection of Vehicle Vibration and Noise Signal Based On Negative Entropy Detection Algorithm

As an important part of vehicle noise signal detection and processing, negative entropy detection algorithm can accurately reduce the number of speech coding bits, ameliorate the recognition accuracy, and establish the noise model in the process of noise reduction. Based on this, this paper first analyses the source and control of vehicle vibration and noise, then studies the principle of negative entropy detection algorithm of vehicle vibration and noise signal, and finally gives the vehicle vibration and noise signal detection method based on negative entropy detection algorithm.

Calculation Method of Working Rotational Angle of Automobile Transmission System and Its Applications

The working state and operating parameters of the automobile transmission system play a key role in the vehicle noise and vibration performance. Based on the basic calculation method of relative rotational angle, this paper proposes two methods for calculating the working rotational angle and torsional stiffness of the transmission system, which can effectively obtain the key information of the transmission system under the vehicle operating state. The working rotational angle, whose initial angle should be corrected by the average angle in the neutral gear coasting condition, can reflect the actual working state of the torsional vibration damper effectively. And the accuracy of the linear torsional stiffness obtained will be above 90%. Both simulation and experimental analysis results show that these two proposed application methods have high calculation accuracies and engineering feasibility.

ASSESSMENT OF THE ROAD NOISE IMPACT ON THE LIVING CONDITIONS IN URBAN AREAS

В современных городах отмечается устойчивый рост автомобильного транспорта, что служит условием формирования акустического дискомфорта и причиной появления некоторых экологически обусловленных заболеваний у населения. Приведено описание методики натурных экспериментов по измерению уровня шума в городской среде в различных условиях. Проведена оценка уровня автотранспортного шума в зависимости от расстояния между первой полосой движения и жилой застройкой. Исследовано влияние шума на условия среды обитания в жилых помещениях при открытых и закрытых створках окон, а также в режиме проветривания в дневное и вечернее время суток. Установлена экспериментальная зависимость эквивалентного уровня автотранспортного шума от этажности жилых зданий. In modern cities there is a steady growth of road transport, which serves as a condition for formation of the acoustic discomfort that leads to the emergence of some environmentally caused diseases. The article describes the methodology of field experiments for measuring noise level in an urban environment under various conditions. The level of motor vehicle noise was assessed depending on the distance between the first traffic lane and residential buildings. The influence of noise on the living environment conditions in residential premises with open and closed windows, as well as in the mode of ventilation both in the day and evening time. As well we established the experimental dependence of the equivalent level of motor vehicle noise on the number of floors of residential buildings.

UNNES Green Transportation as a Continuous Effort in Building a Conservation University

Universitas Negeri Semarang (UNNES) declared itself as a conservation university with 3 main pillars, namely: (1) values and character, (2) arts and culture, and (3) natural resources and physical environment. UNNES believes the environmental crisis cannot be overcome only through practical and technical actions but it also attempts to change the way humans view and behave towards the environment. One indicator of natural resources pillars and the environment is green transportation. To implement green transportation, UNNES develops an internal transportation system to guide the use of vehicles, roads and parking areas on the campus. The use of regulated vehicles included motorized and non-motorized vehicles. The target of implementing a green transportation system was to reduce emissions in the campus environment to a minimum level. Motorized vehicles must obey the directional traffic signs applied in the campus environment and be only allowed to park in designated parking areas. Sufficient space for bicycle traffic, environmentally-friendly vehicles, and pedestrians on the sideways were preferred. Motor vehicle noise levels must not exceed 55 dB. Special vehicle traffic, among others, such as garbage transporters, watering plants, fire engines, and special-licensed vehicles were regulated under applicable regulations. Inspection tasks were carried out by security vehicles that can go through all roads in the campus environment in the direction of the designated lane, except in unlikely emergencies. Environmentally-friendly vehicles in the form of electric and non-fossil cars operated on Monday-Friday from 6:00 to 18:00 and were free. Markings with different colors, and bicycle lanes were used to differentiate between motorized vehicles. Campus parking points consisted of a central parking point and several auxiliary parking units. The central parking in the Multi-purpose Building was used for motorized vehicles or bicycles and was guarded 24 hours. Meanwhile, the auxiliary parking units were located in each work unit area which also had a security system. People with disabilities were facilitated through special signposts.

Acoustical Materials: Solving the Challenge of Vehicle Noise

For a limited time only, SAE is offering a 20% discount off the list price of $70. Purchase today for $56. What is acoustics? What is noise? How is sound measured? How can the vehicle noise be reduced using sound package treatments? Pranab Saha answers these and more in Acoustical Materials. Acoustics is the science of sound, including its generation, propagation, and effect. Although the propulsion sources of internal combustion engine (ICE) vehicles and electric motor-powered vehicles (EV) are different and therefore their propulsion noises are different, both types of vehicles have shared noise concerns: Tire and road noise Wind noise Vehicle noise and vibration issues have been there almost from the inception of vehicle manufacturing. The noise problem in a vehicle is very severe and is difficult to solve only by modifying the sources of noise and vibration. Sound package treatments address the noise and vibration issues along the path to reduce in-cabin noise. In Acoustical Materials, readers will grasp the science of reducing sound and vibration using sound absorbers, sound barriers, and vibration dampers. Sound provides information on the proper operation of the vehicle, but if unchecked, can detract from the consumer experience within the vehicle and create noise pollution outside the vehicle. Acoustical Materials provides essential information on the basics of sound, vehicle noise source, how these are measured, how vehicle owners perceive sound, and ultimately, how to solve noise problems in vehicles using sound package materials.