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The purpose of this paper is to propose a unified optimization design method and apply it to handle the brake squeal instability involving various uncertainties in a unified framework.

Fuzzy random variables are taken as equivalent variables of conventional uncertain variables, and a unified response analysis method is first derived based on level-cut technique, Taylor expansion and central difference scheme. Next, a unified reliability analysis method is developed by integrating the unified response analysis and fuzzy possibility theory. Finally, based on the unified reliability analysis method, a unified reliability-based optimization model is established, which is capable of optimizing uncertain responses in a unified way for different uncertainty cases.

The proposed method is extended to perform squeal instability analysis and optimization involving various uncertainties. Numerical examples under eight uncertainty cases are provided and the results demonstrate the effectiveness of the proposed method.

Most of the existing methods of uncertainty analysis and optimization are merely effective in tackling one uncertainty case. The proposed method is able to handle the uncertain problems involving various types of uncertainties in a unified way.

Friction vibrations and noises which are common in brakes, have attracted a great deal of attention lately. This paper analyses low frequency vibrations in disc brakes excited at high car speed. This vibration, called judder, has a frequency in the range 10 to 300 Hz and usually comes in association with hum noises. The dynamic phenomenon shows two principal components, one normal and the other one tangential to the disc brake surface. It is explained how variations of friction coefficient, and thermoelastic instability caused by the tangential component, contribute to the appearance of judder. A numerical analysis in 3D using the finite element method has been implemented combining both tangential and normal components, and solving the thermoelastic process. Special attention is dedicated to the simulation of the thermoelastic process showing the correlation with experiments.

The purpose of this paper is to design an improved parallel regenerative braking system (IPRBS) for electric vehicles (EVs) that increases energy recovery with a constant brake pedal feel (BPF).

The conventional hydro-mechanical braking system is redesigned by incorporating a reversing linear solenoid (RLS) and allowed to work in parallel with a regenerative brake. A braking algorithm is proposed, and correspondingly, a control system is designed for the IPRBS for its proper functioning, and a mathematical model is formulated considering vehicle drive during braking. The effectiveness of IPRBS is studied by analyzing two aspects of regenerative braking (BPF and regenerative efficiency) and the impact of regenerative braking contribution to range extension and energy consumption reduction under European Union Urban Driving Cycle (ECE).

IPRBS is found to maintain a constant BPF in terms of deceleration rate vs pedal displacement during the entire braking period irrespective of speed change and deceleration rate. The regenerative ratio of IPRBS is found to be high compared with conventional parallel regenerative braking, but it is quite the same at high deceleration.

A constant BPF is achieved by introducing an RLS between the input pushrod and booster input rod with appropriate controller design. Comparative analysis of energy regenerated under different regenerative conditions establishes the originality of IPRBS. An average contribution ratio to energy consumption reduction and driving range extension of IPRBS in ECE are obtained as 18.38 and 22.76, respectively.

The main purpose of this study is to analyse the thermomechanical behavior of the dry contact between the brake disc and pads during the braking phase.

The simulation strategy is based on computer code ANSYS11. The modeling of transient temperature in the disc is actually used to identify the factor of geometric design of the disc to install the ventilation system in vehicles. The thermal‐structural analysis is then used coupling to determine the deformation and the Von Mises stress established in the disc, the contact pressure distribution in pads.

The analysis results showed that temperature field and stress field in the process of braking phase were fully coupled.

The results are satisfactory when compared with those of the specialized literature.

The purpose of this paper is to report a research in which creative design concepts have been applied for braking system synchronization in two wheeler bikes.

Literature review on creative design concepts and braking system scenario has been carried out. By studying the existing braking system and applying creative design concepts, modified braking system has been developed.

The research experience indicated that the effectiveness of braking system has been improved by the adoption of proposed system.

The research has been carried out for an automobile two wheeler. The findings of this research work could be extended to similar models of two wheelers.

The usage of the proposed system reduces the number of accidents and it adds significantly to the life of the brakes.

A case study has been reported to indicate the application of creative design concepts for enhancing the synchronization of automotive braking system in two wheeler bikes.

This paper aims to deal with the synergistic effect of steel slag-molybdenum disulfide particles on fade-recovery performances of non-asbestos organic friction material.

The brake friction materials were developed by using steel slag and molybdenum disulfide particles as individual and combination in the formulation. The brake friction materials were developed in the form of standard brake pads as per the industrial practice. The physical, mechanical and thermal properties of the developed brake pads were tested as per the industrial standards. The tribological properties were analyzed using the Chase test as per IS2742-Part-4. Worn surface analysis was done using a scanning electron microscope.

The experimental results indicate that the brake pads filled with a combination of steel slag and molybdenum disulfide showed stable friction and less wear rate due to the synergetic nature of abrasive and lubricant.

This paper explains the influence of steel slag and molybdenum disulfide particles as individual and combined in brake pads formulation to enhance the tribological performance by producing stabilized friction with undulations.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2020-0216/

This paper aims to develop of magnetic field controlled friction braking technology, a novel brake friction material with magnetic was designed and prepared in this paper.

The permalloy, a soft magnetic material, was selected as an additive to design and prepare the magnetic brake material. The friction, wear performance and permeability of each brake pads were investigated by experiments. By choosing the performance of friction coefficient fluctuation, friction coefficient deviation and mean wear rate as optimization parameters, the formulation of the magnetic friction material was optimized based on Fuzzy theory by using analytic hierarchy process methods and SPSS software.

The results showed that the developed soft magnetic friction material has not only superior friction coefficient, permeability and inferior wear rate but also good physical and mechanical properties.

Permalloy powder was added to the formulation of friction material to achieve a new functional friction material with high magnetic permeability. It is believed that this research will be of great theoretical and practical significance to develop both new brake materials and active control technology of the braking process in the future.

THE airframe systems division of Lucas Aerospace are involved in producing the high lift and wing sweep control unit for which the design rights are shared with Microtecnica SpA who hold the contract.

A dynamic model of the brake system considering the tangential and radial motion of the pad, and the torsion and wobbling motion of the disk is established in this paper. The influence of radial stiffness on the brake system is investigated under different tribological conditions. This paper aims to prove that sufficient radial stiffness is indispensable in the design of the brake system with good tribological performance.

By using the lumped mass method, a dynamic model of the brake system is established. A Stribeck-type friction model is applied to this model to correlate the frictional velocity, pressure and friction force. The stability of pad vibration is analysed by analysis methods. A new stability evaluation parameter is proposed to study the influence of radial stiffness on stability of pad vibration in a certain friction coefficient brake pressure range.

The findings show that the tangential vibration of the pad transits from periodic motion to quasi-periodic motion under a low tangential stiffness. The influence of radial stiffness on motion stability is stronger under a low nominal brake radius. The stability of the brake system can be ensured when the brake radius and radial stiffness are sufficient.

The influence of tangential stiffness of pad on stability of the brake system has been researched for decades. The insufficiency of stiffness in radial direction may also generate certain levels of instabilities but has not been fully investigated by modelling approach. This paper reveals that this parameter is also strongly correlated to nonlinear vibration of the brake pad.

A parallel finite‐element/multi‐body‐dynamics investigation is carried out of the effect of up‐armoring on the off‐road performance of a prototypical high‐mobility multipurpose‐wheeled vehicle (HMMWV). The paper seeks to investigate the up‐armoring effect on the vehicle performance under the following off‐road maneuvers: straight‐line flatland braking; straight‐line off‐angle downhill braking; and sharp left turn.

For each of the above‐mentioned maneuvers, the appropriate vehicle‐performance criteria are identified and the parameters used to quantify these criteria are defined and assessed. The ability of a computationally efficient multi‐body dynamics approach when combined with a detailed model for tire/soil interactions to yield results qualitatively and quantitatively consistent with their computational counterparts obtained using computationally quite costly finite element analyses is assessed.

The computational results obtained clearly reveal the compromises in vehicle off‐road performance caused by the up‐armoring employ to improve vehicle blast and ballistic protection performance/survivability. The results obtained are also analyzed and explained in terms of general field‐test observations in order to judge physical soundness and fidelity of the present computational approaches.

The paper offers insights into the effects of up‐armoring of the HMMWV on off‐road vehicle performance.