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This paper aims to design an active shock absorber scheme for use in conjunction with a passive shock absorber to suppress the horizontal vibration of elevator cars in a smaller range and shorter time. The developed active shock absorber will also improve the safety and comfort of passengers driving in ultra-high-speed elevators.

A six-degree of freedom dynamic model is established according to the position and condition of the car. Then the active shock absorber and disturbance compensation-based adaptive control scheme are designed and simulated in MATLAB/Simulink. The results are analysed and compared with the traditional shock absorber.

The results show that, compared with traditional spring-based passive damping systems, the designed active shock absorber can reduce vibration displacement by 60%, peak acceleration by 50% and oscillation time by 2/3 and is more robust to different spring stiffness, damping coefficient and load.

The developed active shock absorber and its control algorithm can significantly reduce vibration amplitude and converged time. It can also adjust the damping strength according to the actual load of the elevator car, which is more suitable for high-speed elevators.

The objective of this work is to introduce a new method to carry out design optimization of a mechanical system for vibration and shock isolation, in particular, the viscous spring isolator mounting system for a forging hammer.

The system dynamics model for an isolated foundation and solution technique for obtaining system response under impact loads is introduced. A design optimization problem is formulated to minimize the maximum impact force transmissibility under design constraints, using stiffness and damping coefficients of the isolator, mass of the foundation block and support area of soil as design variables. A dedicated simulated annealing (SA) algorithm is applied to solve the optimization problem.

Viscous spring isolator mounting system, if properly designed, can considerably reduce shock and vibration transmission and the size of the foundation. The optimization leads to a mounting system with superior impact and vibration isolation capability over conventional designs. Sensitivity study and design optimization on a typical 3‐ton forging hammer has demonstrated the advantages of the new design method.

To further improve the accuracy of the design optimization, a more detailed system dynamics model might be introduced.

The work leads to a better design method for viscous spring isolator foundation systems.

This study forms the foundation for further research on design optimization of viscous spring isolator foundation systems, and contributes to the application of SA optimization technique to engineering design.

A local equivalent linearization methodology is proposed to simulate non‐linear shock absorbers and dual‐phase dampers in the convenient frequency domain. The methodology based on principle of energy similarity, characterizes the non‐linear dual‐phase dampers via an array of local damping constants as function of local excitation frequency and amplitude, response, and type of non‐linearity. The non‐linear behaviour of the dual‐phase dampers can thus be predicted quite accurately in the entire frequency range. The frequency response characteristics of a vehicle model employing non‐linear dual‐phase dampers, evaluated using local linearization algorithm, are compared to those of the non‐linear system, established via numerical integration, to demonstrate the effectiveness of the algorithm. An error analysis is performed to quantify the maximum error between the damping forces generated by non‐linear and locally linear simulations. The influence of damper parameters on the ride improvement potentials of dual‐phase dampers is further evaluated using the proposed methodology and discussed.

This paper aims to detail the qualification of alternative substrate materials and reliability aspects for quad flat no lead (QFN) packages for highly stressed electronic devices, e.g. for use in automotive applications.

Detailed information is given on the advanced climatic and mechanical requirements that electronic devices have to withstand during life cycle testing to qualify for the automotive industry. Studies on the suitability of high‐temperature thermoplastics as substrate materials for printed circuit boards and the qualification of QFN packages for advanced requirements are described. In addition, information on cause‐effect relationships between thermal and vibration testing are given.

With respect to adhesion of metallization on high‐temperature thermoplastics and the long‐term stability of the solder joints, these substrate materials offer potential for use in electronic devices for advanced requirements. In addition, the long‐term stability of the solder joints of QFN packages depends on the design of the landings on the PCB and the separation process of the components during manufacturing.

The paper covers only a selection of possible high‐temperature thermoplastic materials that can be used in electronics production. Also, this paper has a focus on the new packaging type, QFN, in the context of qualification and automotive standards.

The paper details the requirements electronic devices have to meet to be qualified for the automotive industry. Therefore, this contribution has its value in giving information on possible substrate alternatives and the suitability for the usage of QFN components for highly stressed electronic devices.

The effect of gold (Au) on the reliability of 0.65 mm pitch surface mount solder joints between plastic quad flat packs and Cu‐Ni‐Au FR‐4 printed circuit boards was investigated. Cu‐Ni‐Au is a desirable printed circuit board finish for multi‐chip modules or printed circuit boards that would otherwise require a selective Au finish, for example for edge connectors or wire bondable parts. However, Au is known to embrittle solder when it is present in sufficiently high concentrations, creating a concern that solder joint fatigue life in service will also be adversely affected. This paper reports the results of mechanical shock, mechanical vibration and thermal cycling testing of fine pitch solder joints containing varying amounts of Au. Tests were performed on as‐soldered joints and on joints that had been heat‐treated to evolve the microstructure towards equilibrium. The tests were designed to accelerate in‐service conditions in a typical industrial environment. Under these conditions, the Au concentrations tested did not promote solder joint failures. Microstructural characterisation of the distribution and morphology of the Au‐, Ni‐ and Cu‐Sn intermetallics in the joint before and after accelerated testing was also performed. On the basis of these observations it is recommended that the Au concentration in solder joints between plastic quad flat packs and Cu‐Ni‐Au FR‐4 printed circuit boards not exceed 3.0 wt.%.

Suspension is a significantly important component for automotive and railway vehicles. Regenerative hydraulic-electric shock absorbers (RHSA) have been proposed for the purpose of attenuating vibration of vehicle suspension, and also recover kinetic energy originated from vehicle vibration that is conventionally dissipated by hydraulic dampers. To advance the technology, the paper aims to present an RHSA system for heavy-duty and railway vehicles and create a dynamic modelling to discuss on the development process of RHSA model.

First, the development of RHSA dynamic model can be resolved into three stage models (an ideal one, a second one with an added accumulator and a third one that considers both accumulator and system losses) to comprehensively evaluate the RHSA's characterisation. Second, a prototype is fabricated for testing and the results meet desired agreements between simulation and measurement. Finally, the study of key parameters is carried out to investigate the influences of hydraulic-cylinder size, hydraulic-motor displacement and accumulator pre-charged pressure on the RHSA system.

The findings of sensitivity analysis indicate that the component design can satisfy the damping characteristics and power performance required for heavy-duty vehicle, freight wagon and typical passenger train. The results also show that reducing the losses is highly beneficial for saving suspension energy, improving system reliability and increasing power-conversion efficiency.

The paper presents a more detailed method for the development and analysis of a RHSA. Compared with the typical shock absorbers, RHSA can also recover the vibration energy dissipated by suspension.

Briefly outlines the nature of vibrations and some of the factors to be considered in their measurement and analysis. Acts as an introduction to the surveyor or engineer who does not normally deal with vibrations, but who is aware that he may experience problems with them.

The problem of hydrogen embrittlement has been approached in a less theoretical manner than in some previous investigations. Factors were considered which could be utilized to minimize embrittlement in processing especially with the higher strength steels which suiter mostly.

The purpose of this paper is to describe the techniques and technologies used in a selection of sensors which operate in extreme environments.

Following a short introduction, this paper discusses the technologies used in a range of sensors, principally accelerometers and pressure, temperature and displacement sensors, used in environments characterised by elevated temperatures, radiation and high shock and vibration levels.

The paper shows that a range of different strategies is employed to allow sensors to operate in extreme environments. These include specialised designs, novel sensing technologies and others which are inherently capable of withstanding extreme conditions and materials which can perform in, or which are resistant to, these environments. Several new technologies are under development which aim to extend sensor performance to new levels.

This paper provides details of the technologies used in a range of sensors aimed at applications in extreme environments.

In the preface the author opens his remarks with ‘This book is intended for students, for newcomers to the aircraft industry, for practising designers and for research workers in the field of stability and control’. This is a most ambitious proposal and it should be stated, right at the beginning, that, taking the book as a whole, the author has succeeded in his objectives. The book is subdivided into three parts, Part I is devoted to longitudinal motion, Part II is concerned with lateral motion while Part III is entitled ‘Stability and Design’. Before proceeding to the text however there is a most comprehensive list of notation which is commendable and it gives an indication of the thoroughness and care of presentation which is reflected throughout the rest of the book.