The present study deals with vital aspects of technological assembly process modeling and simulation based on application of the MTBF (Mean Time Between Failures) parameter, as exemplified upon experimental assembly of an automobile disc brake caliper unit. The proposed simulation model of the analyzed assembly work cell is hereby expounded upon. The paper further presents the outcomes and conclusions of the undertaken experimental procedure.

Model-based systems engineering (MBSE) is an approach to improve traditional document-based systems engineering approach through the use of a system model. In the current practice of system developments, there exists a large gap between systems engineering activities and engineering analyses, because systems engineers and engineering analysts are using different models, tools and terminology. The gap results in inefficiencies and quality issues that can be very expensive. This work presents an integrated modeling and analysis capability that bridges the gap. The technical approach is based on integrating SysML modeling tools with process integration and design optimization framework. This approach connects SysML models with various engineering analysis tools through a common interface. A capability was developed to automatically generate analysis models from a system model and then execute the analytical models. Requirements conformance analysis was performed using results of engineering analysis. A technique was developed to define optimization problems in SysML, where requirements were used as design constraints. The integrated system modeling and analysis capability was demonstrated using an automobile brake pad design example. The integrated toolset was used to understand impacts of requirements changes in the SysML model and to find a new design that meets the new requirements through engineering design optimization.

The paper presents the development of a novel type of drum brake capable of locking a joint exploiting the effect of self excitation characteristic of this type of brake. A theoretical analysis based on the Reye assumption on wear is first presented, were conditions for self excitement are determined. An initial version of the brake was designed and tested, but it was soon discovered that actuation with solenoids was not appropriate. A second version was then developed where solenoids were replaced by a small motor and reducer placed inside the brake itself, but the resulting drum was too big for the application. Finally a version were the motor and reducer were placed outside the drum was designed. An ad hoc experimental test bed was built using a Maxon motor to control rotation and toque of the drum and to allow an initial wear of the ferodo in order to obtain compliant surfaces. Finally an electronic control of the brakes has been developed.

Due to increased interest in comfort features, considerable effort is spent by brake manufacturers in order to suppress brake squeal. This process can be shortened by eliminating the remaining squealing with shunted piezoceramics that are embedded into the brake system. The piezoceramic offers the unique ability to convert mechanical energy into electrical energy and vice versa. The damping performance is determined by the connected shunt. This paper presents a multibody system of a brake, which is capable to reproduce the important features of brake squeal. It includes the dynamics of a piezoceramic that is shunted with a passive LR shunt or a negative capacitance LRC shunt. Analytical stability analysis are carried out to obtain optimal shunt parameters. The performance increase with a negative capacitance is studied in detail. The simulations are validated with measurements on an automotive disc brake.

Mathematical modeling is the process of designing a model of a real system and conducting experiments with it for the purpose of understanding the behaviour of the system. Mathematical simulation is widely used for investigating and designing the compressors. Investigations of the processes of reciprocating compressors using mathematical models is an effective tool by high development of computing technique, which enables complicated problems to be solved with a minimal number of simplifying assumptions. A considerable number of previous works has been done on the mathematical modeling and simulation. The aims of the present work are to construct a model which is easy to understand, easy to detect errors in the process of building a model and easy to compute a solution. This project presents a simplified and effective mathematical model for the estimation of reciprocating compressor performance using personal computers that can be easily handled. The effect of various physical parameters, like, clearance volume, cylinder diameter, connecting rod length, crank radius, valve lift and other dimensions, etc., and operating parameters, like, discharge pressure, compressor speed, etc., on thermodynamic behaviour of compressor in working condition has been analysed. The model has been developed for obtaining cylinder pressure, cylinder volume, cylinder temperature, valve lift and resultant torque at different crank angles and free air delivered and indicated power of the compressor.

In this paper, the dynamic behavior of disc brake is presented considering five degrees of freedom system and a formula representing the variation of friction coefficient with applied load, temperature, velocity and design is considered. In addition, the surface distortion and roughness of the disc are assumed to vary harmonically. The influences of the Tribological properties of the pad’s friction material and the surface roughness and distortion of the disc on the system stability are studied. The effect of other parameters such as, static friction coefficient, contact stiffness and damping between pad and caliper, position of the load application by piston on the disc brake stability is also investigated and discussed. The study concluded that, disc brake vibrations can be controlled by optimizing the previously mentioned parameters. And disc surface irregularities and distortion contribute in increasing vibration levels in disc brake systems.