Engine Vibration Research Articles

Frequency response sensitivity to crack for piezoelectric FGM beam subjected to moving load

Since functionally graded material (FGM) is increasingly used in high-tech engineering, free and forced vibrations of FGM structures become an important issue. This report addresses the analysis of frequency response sensitivity to crack for piezoelectric FGM beams subjected to moving load. First, a frequency domain model of a cracked FGM beam with a piezoelectric layer is conducted to derive an explicit expression of the electrical charge produced in the piezoelectric layer under the moving load. It was shown in the previous works of the authors that the electrical charge is a reliable representation of the beam frequency response to moving load and can be efficiently employed as a measured diagnostic signal for structural health monitoring. Then, a damage indicator acknowledged as a spectral damage index (SDI) calculated from the electrical frequency response is introduced and used for sensitivity analysis of the response to crack. Under the sensitivity analysis the effect also of FGM and moving load parameters on the sensitivity is examined and illustrated by numerical results.

Finite-Time Disturbance Observer-Based Adaptive Course Control for Surface Ships.

In this paper, a finite-time disturbance observer-based adaptive control strategy is proposed for the ship course control system subject to input saturation and external disturbances. Based on the Gaussian error function, a smooth saturation model is designed to avoid the input saturation of the system and reduce steering engine vibrations, and an auxiliary dynamic system is introduced to compensate for the effect of the rudder angle input inconsistency on the system. By constructing an auxiliary dynamic, a finite-time disturbance observer is designed to approximate the external disturbance of the system; an adaptive updating law is also constructed to estimate the upper bound of the derivative of the external disturbance. Combining the finite-time disturbance observer with the auxiliary dynamic system, a novel adaptive ship course control law is proposed by using the hyperbolic tangent function. Moreover, according to LaSalle's Invariance Principle, a system stability analysis method with loose stability conditions and easy realizations is designed, while the stability of the closed-loop system and the ultimately uniformly boundedness of all its signals are proven. Finally, the course control simulation analysis of a surface ship is carried out. The results show that the proposed control law has a strong resistance to external disturbances and a strong non-fragility to system parameter perturbations, which ensure that the course control system has great control performance.

Study on damping performance of non-ideal particle-tuned inerter damper

Aiming at the shortcomings of the current particle dampers and the needs of civil engineering vibration damping, while considering the damping in the non-ideal inertial vessel, a new type of non-ideal particle tuned inerter damper (NPTID) is proposed. Firstly, the construction and technical realization of NPTID are introduced, the mechanical model of NPTID is proposed based on the principle of energy dissipation by particle collision, and the motion control equations of the single-degree-of-freedom structure with an additional NPTID are established; then three natural seismic waves and one artificial seismic wave are selected as the external excitations, and the damping performance of the NPTID is analyzed; finally, the influence of key parameters on the control effect of the NPTID is investigated by parametric analysis. The results show that NPTID has good control effect, and can realize the reduction ratio of more than 43% by utilizing a 0.1% particle mass ratio.

Evaluation of steering wheel vibration in electric vehicles and application to Dynamic Motor Drive

Eliminating steering wheel vibration is a key in refining vehicle Noise, Vibration, and Harshness (NVH). The absence of masking engine noise and vibration makes this challenge harder in a pure electric vehicle. This paper provides three key insights with regards to the evaluation of steering wheel vibration in EVs using on-road test data. First, we explore the effects of steering wheel grip variation in the measured accelerometer response. Second, we identify the limitations of evaluating powertrain induced vibration in a noisy environment and propose a post-processing technique to reject irregular road-induced perturbations from the measured data. Third, we evaluate a tuned mass absorber as a localized mitigation tool for steering wheel vibration. Finally, we describe how the above techniques were brought together to deliver a refined NVH experience while integrating Dynamic Motor Drive (DMD) technology as a software-only solution which has been shown to improve EV range by 0.4% on IPM and 3% on EESM based vehicles.

Optimization of Performance, Emissions, and Vibration in a Hydrogen-Diesel Dual-Fuel Engine Using Response Surface Methodology

Background: Dual-fuel diesel engines using hydrogen as a secondary fuel source are a promising technology for reducing emissions while maintaining engine performance. However, optimizing these engines for all three aspects (performance, emissions, and vibration) simultaneously presents a challenge. Objective: This study aimed to address this challenge by employing Response Surface Methodology, a statistical technique used to optimize multi-variable processes. The goal was to find the ideal combination of engine load, hydrogen flow rate, and compression ratio that would maximize Brake Thermal Efficiency while minimizing Brake-Specific Fuel Consumption, Nitrogen Oxide emissions, and engine vibration. Method: A Box-Behnken design, a specific type of design optimization with three factors and three levels, was employed. The experiment evaluated the impact of three key factors: engine load (ranging from 0 - 12 kg), hydrogen flow rate (0-15 L/min), and compression ratio (16 to 18:1). The effects of these factors on performance, emissions, and vibration were measured. Results: The results revealed a trade-off between achieving optimal performance and minimizing emissions. The highest Brake Thermal Efficiency and lowest Brake-Specific Fuel Consumption were achieved at a high compression ratio (18:1), maximum hydrogen flow rate (15 L/min), and under full engine load (12 kg), corresponding to a brake power of 3.5 kW. However, these conditions also resulted in higher NOx emissions and vibration levels. Conversely, minimizing NOx and vibration occurred at a lower compression ratio (16:1), with the same maximum hydrogen flow rate (15 L/min), but at a significantly reduced engine load (3 kg), resulting in a much lower brake power of 0.875 kW. Conclusion: These findings highlight the complex relationship between performance, emissions, and vibration in a hydrogen-diesel dual-fuel engine optimized using Response Surface Methodology. While optimal conditions were identified for specific goals, achieving all desired characteristics simultaneously across the entire operating range remains a challenge.

Rolling table centrifuge modelling of partially saturated granular material to inform on instability during solid bulk cargo transport

The response of partially saturated granular cargoes during maritime transportation has resulted in the capsize and sinking of 27 bulk carriers at sea and the loss over 90 seafarers’ lives in the last decade. The partially saturated granular material response to energy imparted during cargo loading, ship engine vibrations and vessel rolling motions from sea states causes a change in state of the granular cargo, which can lead to vessel instability and ultimately capsize. However, the mechanisms driving the response of partially saturated granular cargos within a bulk carrier hold are not well understood. This paper presents results from an experimental study of rolling table centrifuge model tests on a partially saturated silica sand to contribute to improved understanding of the response of granular cargoes during maritime transport. Observed settlement, pore pressure, moisture content and density changes during and/or following a sequence of large amplitude rolling motions are presented. The results indicate that for the conditions considered, a progressive upwards migration of pore water during rolling led to creation of a free surface of water above the granular sample that was left in a denser, lower moisture content sample compared to its initial state. Sloshing of free water on top of even a competent cargo during rolling motions of the ship can contribute to loss of ship stability and ultimately capsize.

The impact of hydrogen injection pressure and timing on exhaust, mechanical vibration, and noise emissions in a CI engine fueled with hydrogen-diesel

The hydrogen-diesel dual-fuel mode is an efficient way of lowering exhaust emissions from compression-ignition engines. Along with exhaust emissions, mechanical vibration and noise emissions are also problems for these engines. In dual fuel mode, it is possible to reduce all emissions by using the appropriate injection strategy. In this study, different injection strategies were used in an engine with an ECU-controlled liquid and gas fuel system. In experiments, constant load (5 Nm), constant speed (1850 rpm), constant hydrogen energy ratio (12%), 4 different hydrogen injection pressures (1, 1.5, 2.0, and 2.5 Bar), and 5 different hydrogen injection starts (25, 35, 45, 55, and 65 °CA aTDC) were performed. In the study, exhaust, mechanical vibration, and noise emissions were recorded and analysed. When a few of the study's data were looked at, it was determined that CO2 emissions decreased by 33.4% and PM emissions by 40.7% at 25 °CA aTDC injection start and 2.5 bar injection pressure. Under the same experimental conditions, NO emissions increased by 8.7%, mechanical vibration emissions increased by 19.9%, and noise emissions increased by 2 dBA.

Preface

Abstract This collection includes accepted papers from the 2024 3rd Workshop on Material Science, Modelling, Engineering, and Applications in Vibration Engineering (MVE 2024). With a special focus on material science, MVE 2024 welcome research papers on the relationship between structure, properties, and uses of materials (including metals, ceramics, glasses, polymers, energy materials, electrical materials, composite materials, fibers, nanostructured materials, nanocomposites, and biological and biomedical materials). In MVE 2024, we have received 29 submissions and 17 are accepted after peer review carried out in Morressier online submission system, with 48 reviewers participated. The final acceptance rate is 58%. For cost efficiency and eco-protection considers, the webinar of MVE 2024 (Almaty, Kazakhstan) provides free access to all attendees and audiences through TencentMeeting. The webinar consists three parts, keynote speech by Prof. Muhammad Suyfan Javed, oral speeches and posters. The keynote speech lasts for 30 minutes and each oral speech is assigned with 15 minutes of presentation and 5 minutes for Q&A. The posters are presented on the webinar and the website for further post-webinar communications. Though poster presenters are not able to get instant communication with audience, they are given opportunities to get connected via emails. Among the seventeen papers in the proceedings, five papers, including Hydration characteristics and kinetic analysis of polyacrylamide (PAM) anti-dispersion cement-based materials, Dynamic analysis of a hydraulic motor lifting auxiliary beam of monorail crane, Research of localization of vibration under strong disturbances using modal analysis methods, Research on seismic response and enhanced resistance support of cross fault tunnel models in healthcare, Experimental study on the influence of different sampling methods on the stress-strain and strength characteristics of weathered and water rich sandstone, are presented with oral speeches. The rest papers are all presented with posters. The proceedings editors hope that this collection can provide guidance for problem solving and further studies. List of General Chair and Technical Program Committee are available in this Pdf.

IoT-Based Vehicle Monitoring System on LoRa Network: Addressing Community Needs in Indonesia

Our innovative IoT-based vehicle monitoring system emerges from a comprehensive survey among vehicle owners. The device circuit is designed using ESP32, GPS to detect location and speed, MPU6050 to detect vibrations from the vehicle engine, and a relay that is used to disconnect the vehicle socket if needed. The data collected from each component is sent through the LoRa Antares network. Access to the data can be done using a cell phone through the MOTRAV application that has been integrated with the Antares server. The designed system is able to display the location, speed, and condition of the vehicle consistently with an average delay of 7 seconds and can receive 65% of the control signals to start and stop the vehicle engine. The system can also send a warning notification if the vehicle that is not being used is detected at a speed of more than 5.5 km/h with engine vibrations detected reaching 28 vibrations/5 seconds.

Experimental Investigation of Citronella Oil as Bioadditive in Biodiesel Fuel on Diesel Engine Performance, Vibration and Emissions

Experimental Investigation of Citronella Oil as Bioadditive in Biodiesel Fuel on Diesel Engine Performance, Vibration and Emissions

Evaluating the vibrational properties of an engine powered by diesel–biodiesel mixtures containing aluminum oxide nanoparticles

Much research has been done on the performance and emissions of engines using renewable fuels. In some cases, nano additives have been added to these fuels. Although the research results are essential, these fuels should be considered from other aspects. One of these aspects is engine vibrations, which can be related to engine ignition and knocking. In this research, the vibration of an engine and its relationship with knocking and combustion using diesel and alumina nano additives with 30, 60, and 90 ppm dosages in the diesel–biodiesel blend (B5, B10) were evaluated. Experiments were carried out using precise vibration measurement equipment in a single-cylinder, four-stroke engine. The frequency domain transformation, Welch test, Kurtosis, and RMS of acceleration were used to analyze the vibrations. The advantages and disadvantages of each method were investigated on the vibrations of each fuel blend. The results showed that despite being more complicated, the Welch test better shows the difference between fuels and their vibration. By this method, it was found that diesel fuel has the lowest vibrations at frequencies below 10 kH, but it has the highest vibrations at frequencies above 10 kH. Also, with diesel and adding alumina nanoparticles to the fuels of B5, the engine performance becomes more erratic despite increasing engine power.

Finite element simulation analysis of vibration transmission characteristics of double shell based on ANSYS

Ship noise contains a large number of low-frequency line spectrum features. It is difficult to distinguish where they come from and even more difficult to identify the ship’s target types using the line spectrum. Therefore, research on ship targets’ vibration transmission characteristics and radiation noise is of great importance for underwater target recognition. From the perspective of underwater acoustic target recognition, this article establishes a simplified finite element model of the double shell using ANSYS, calculates the displacement response of the double shell under harmonic loads, and conducts modal analysis, harmonic response analysis, and transient dynamic analysis, which verifies the consistency of vibration between the inner shell and outer shell. Marine experimental data show that the low-frequency line spectrum of ship noise is related to the vibration frequency of ship main engines. It may be caused by diesel engine vibration transmitted through ship hull vibration and can be used as an auxiliary feature for underwater acoustic target recognition.

Chaotic dynamics of granules-beam coupled vibration: Route and threshold

Although granular materials are the second most processed in industry after water, the theoretical study of granules-structure interactions is not as advanced as that of fluid-structure interactions due to the lack of a unified view of the constitutive relation of granular materials. In the previous work [1], the theoretical model of granules-beam coupled vibration was developed and verified by experiments. However, it was also found that the system exhibits significant stiffness-softening Duffing characteristics even under micro-vibration, which implies that chaotic responses may be reached under certain conditions. To reveal the route and critical conditions for the system to enter chaos, in the present work, the chaotic dynamics of the system are studied. In qualitative analysis, Melnikov method is applied to analyze the instability behavior of the perturbed heteroclinic orbit of the system, thus the critical condition for the system to enter Smale horseshoe chaos, i.e., the Melnikov criterion, is obtained. The validity of the criterion is verified numerically. In experimental studies, the existence of chaotic responses and the route to chaos for granules-beam coupled vibrations is revealed. The experimental results suggest that the system response first experiences symmetry-breaking then undergoes a complete period-doubling cascade, and finally enters single-scroll chaos. In addition, although the Additional Dynamic Load (ADL) generated by granular media is highly complicated, a general and simple evolution pattern of the chaos threshold is found by parametric experiments, which is also supported by the Melnikov criterion. In short, the chaotic dynamics of granules-beam coupled vibration is revealed, which is a contribution to the engineering vibration aspect. On the theoretical side, an impressive result lies in that for the first time, the Melnikov criterion of such fractional-order systems is obtained in a global and closed form, which provides, respectively, improvement suggestions and reference results for the existing and future research on chaotic dynamics of fractional-order systems, especially of the Duffing-type systems.

Low-frequency vibration bandgaps and deep learning-based intelligent design method of Y-shaped core sandwich metabeams

In this paper, the wave propagation mechanics theoretical model of Y-shaped core sandwich metabeams with local resonators is established based on the spectral element method, and the flexural wave bandgaps and vibration isolation characteristics are studied. The reliability of the theoretical model of Y-shaped core sandwich metabeams is verified by the finite element method and experiment. On this basis, a deep learning-based intelligent design method for predicting the vibration transmission characteristics and structure design of Y-shaped core sandwich metabeams is proposed. A dataset is created using the theoretical model of wave dynamics, and deep neural networks are constructed to forward prediction of transmission characteristics and intelligent design of Y-shaped core sandwich metabeams, respectively. Results indicate that the bandgap range of Y-shaped core sandwich metabeams is 2.5 times that of Y-shaped core sandwich beams, and the start frequency of bandgap is reduced by 578 Hz. The prediction of the transmission characteristic curve is in good agreement with the target, and the average relative error of intelligent design is below 3 %, which verifies the precision of the intelligent design method. The innovative, intelligent design method provides a novel way to realize engineering vibration reduction design of acoustic metamaterials rapidly.

Diesel engine vibration analysis using artificial neural networks method: Effect of NH3 additive in biodiesels

Diesel engine parameters, such as fuel and its additives, play an essential role in minimising the effects of engine vibration. This study aimed to use artificial neural networks (ANN) to model and analyse diesel engine vibration characteristics at different engine speeds using NH3 as an additive in hazelnut (HD), peanut (PD), and waste-cooking oil (WD) biodiesels. The results showed good correlations between the ANN models and experimental results using regression analysis methods. The ANN models for diesel engines showed high accuracy. The ANN models indicated that a 5 % NH3 additive decreased engine vibration for HD and PD.In comparison, 10 % and 15 % NH3 additive ratios increased engine vibration for HD, PD, and WD due to low combustion quality. The lowest vibration levels occurred with P100, P95A5, P90A10, and P85A15 at 1200 rpm. H100 and H95A5 produced the highest diesel engine resultant vibration (DERV) values. All ANN models generated the lowest and highest DERV values at 1200 rpm and 2100 rpm, respectively. The RMS method showed that H95A5, P85A15, and W85A15 contributed the most to diesel engine vibration. Using a low amount of NH3 additive positively affected DERV for HD and PD but not for WD.

An enhanced strain gradient model for temperature-dependent sound transmission loss in double-walled functionally graded microplates

With the growing use of functionally graded (FG) microplates in structural acoustic metamaterials for aerospace and automotive applications, accurate modeling of sound transmission loss is critical for effective vibration and noise control engineering. In this study, a theoretical model is formulated based on the first-order shear deformation theory (FSDT) to estimate sound transmission loss (STL) through air-filled rectangular double-walled FG microplates with simply supported boundary conditions. The microplates are subjected to a nonlinear thermal environment, and the modified strain gradient theory (MSGT) is employed, incorporating three material length scale parameters to account for the size effect. The material properties are temperature-dependent and vary across the thickness following a power-law distribution. Size-dependent coupled vibroacoustic equations are derived utilizing the sound velocity potential, normal velocity continuity conditions, and Hamilton's principle, and are subsequently solved using the Galerkin method. Comparative analysis is performed by contrasting the results obtained from the MSGT model with those from the modified couple stress theory (MCST) and classical continuum theory (CCT) models, allowing for the assessment of the accuracy and precision of the proposed solution. Additionally, the influence of various parameters, such as gradient index, length scale parameters, temperature variation, incident angles, and acoustic cavity depth, on the STL is investigated. Key findings demonstrate that in the stiffness-controlled region, length scale parameters significantly enhance STL, while power-law index and temperature variation reduce it.

Method of aero-engine flight safety pre-warning based on support vector machine

Engine vibration is a decisive factor in flight safety. Aiming at the problem that the current single vibration warning value of an aero-engine cannot reflect the vibration characteristics of the engine in flight, the estimated probability density of the measured vibration of the engine based on the support vector machine (SVM) method is established, and the aero-engine flight safety pre-warning research is carried out. Through the statistical analysis of the installed flight data of a engine, the probability density function estimation of the measured vibration data of the aero-engine flight was carried out by the support vector machine, and the vibration warning value of the installed engine in each state was determined according to the probability distribution and the general primary side determined by the vibration monitoring limit value of rotating machinery. Through the verification of actual flight data, the determined vibration warning value with the change trend of engine state is consistent with the actual flight data, and is more sensitive to engine failure, which is conducive to improving the early failure warning ability of aero-engine during flight.

Research on Load Control Of Main Bearing Based on Isfd Principle

The main bearing load of the internal combustion engine is one of the main excitation sources that cause the vibration and radiation noise of the body structure. By reducing the main bearing load transmitted from the main bearing cap to the body, the vibration and noise of the internal combustion engine can be effectively reduced. In this paper, the main bearing cap damper is designed based on the principle of integral squeeze film damper (ISFD), and the load is controlled on the transmission path of the main bearing load. The main bearing load measurement scheme is designed. The load changes of the main bearing cap before and after the installation of the main bearing cap damper are measured experimentally. The load control effect of the main bearing cap damper is analyzed and verified.

Optimisation of Exhaust Emissions, Vibration, and Noise of Unmodified Diesel Engine Fuelled with Canola Biodiesel-Diesel Blends with Natural Gas Addition by Using Response Surface Methodology

The paper presents methods to determine the optimum input parameters of CNG addition, biodiesel blend ratio, and engine speed to improve engine responses in terms of exhaust emissions, vibration, and noise of CNG-biodiesel-diesel fuelled engine. Box-Behnken based on response surface methodology was used to predict and optimise input parameters. Variance analysis was applied to determine the significant relationship between the input parameters and engine responses. At optimum input parameters (CNG addition=9.24 L/min, biodiesel blend ratio=40%, engine speed=1524.24 rpm), the optimum engine responses of NOx, CO, CO2, O2, engine vibration acceleration, and noise were 93.77 ppm, 438.05 ppm, 1.47%, 18.59%, 37.17 m/s2 and 91.34 dB[A], respectively. In terms of coefficient determination of R2, the values were 99.11%, 99.22%, 99.41%, 99.70%, 98.65%, and 98.60% respectively. The correlation between the optimised result and the engine test result showed an acceptable error limit for NOx, CO, CO2, O2, engine vibration acceleration, and noise as 4.2%, 3.8%, 4.9%, 0.25%, 4.12%, and 0.17%, respectively.

On formation, annihilation, and evolution of potential wells, and nonlinear phenomena of multi-magnet energy sink system.

This paper investigates the formation, annihilation, and evolution mechanisms of potential energy wells in nonlinear energy sink systems. The nonlinear energy sink system is composed of multiple inner and outer magnets. Two multi-magnet energy sink (MES) architectures are designed: a single-magnet vibrator and a double-magnet vibrator. Multi-stable (bi-, tri-, quad-, penta-, hexa-, and hepta-stable) mechanisms are elaborated by the Poincaré section and bifurcation diagram concerning the magnet length, the link length, and the MES configuration. The results show that the change in the internal structural parameters of the MES system will generate different types of bifurcations (i.e., saddle-node, subcritical, and super pitchfork bifurcations) and phase trajectories and have rich nonlinear response behaviors in the low frequency and wide frequency range, which can be used for damping and vibration reduction of engineering structures, vibration control, and energy source of the microgrid.