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The purpose of this paper is to obtain a more accurate fatigue life of structures by introducing the surface roughness into fatigue life prediction model.

Based on the fatigue life prediction model with surface roughness correction, the shock absorber cylinder is taken as an example to verify the feasibility of the improved method. Based on the load of the shock absorber cylinder during driving, fatigue experiments are performed under longitudinal and lateral forces, respectively. Then, the fatigue life predicted by the modified model is compared with that predicted by the traditional model.

By comparing with the test results, considering the influence of mean stress, the Manson method is more accurate in life prediction. Then, the modified Manson-Coffin and Manson method with surface roughness is more accurate in life prediction under longitudinal force and lateral forces, respectively. This verifies the feasibility of the improved method with the surface roughness.

The research on the influence of surface roughness on fatigue life can lay the technical foundation for the life prediction of products and have great significance to the quality evaluation of products.

The shock absorber is an important component of vehicle suspension that attenuates the vehicle vibration. Its running state directly affects the performance of the vehicle suspension. The purpose of this paper is to quantitatively study the relationship between damping characteristics and air chamber and oil properties in single-tube pneumatic shock absorber.

Combined with the principle of fluid dynamics and hydraulic transmission technology, the rebound stroke and compression stroke mathematical models, and damping characteristics simulation model are established to investigate the effect of the air chamber and oil property on damping characteristics.

Research results show that the initial pressure of the air chamber is the key parameter which influences the damping characteristics of the shock absorber. The change of the initial pressure has more impact on damping force, and less impact on the speed characteristic; the initial volume of the air chamber almost has no effect on the damping characteristics. The density and viscosity of the oil have certain influence on the damping characteristics. Therefore, selecting suitable damping oil is very important.

Using Matlab/Simulink software to build simulation models, its results are very accurate. The conclusions can provide a theoretical reference for the structure design of a single-tube pneumatic shock absorber.

SINCE the original British patent for telescopic oleo‐pneumatic shock absorbers for aircraft landing gear was drawn up in 1915 by Vickers engineer T. S. Duncan — with his invention of the positive recoil damping principle — Weybridge has been in the forefront of landing gear development on all types of aircraft for over half a century. Today, as a member company of British Aircraft Corporation, the Weybridge resources in this field are unique to a prime aircraft manufacturer. The landing gear units for the VC10 and B.A.C. One‐Eleven airliner families and the supporting design, production and testing facilities at Weybridge are among the most advanced in the world.

In a levered suspension undercarriage unit the lever‐arm carrying the landing wheel 15 has fork portions 13, 14, and the shock absorber 33 is mounted offset from the hub 12 and between the members 13, 14 so that it is disposed wholly within the lateral extremities of the wheel 15 and leg 6. The shock absorber cylinder is fitted with trunnions 37 engaging bearings in the fork members 13, 14 and the end of the plunger 38 is connected to a boss 7 at the lower end of the leg 6. A metal cowling 43 encloses the wheel and the member 14 may be circular to serve as the brake torque plate.

DUNLOP LTD were selected to supply the tyres, wheels, and brakes, (hydraulic aspects are dealt with elsewhere). As in all cases of aircraft design, space, weight, performance and cost were of particular importance. The selection of suppliers for the MRCA was no exception when competing against many rivals and the division's experience and technology, particularly in the field of tyre, brake and anti‐skid design was an important factor in the final choice. The capability Dunlop has of type testing such equipment using the most advanced dynamometer in the world was also a contributory factor when developing such an important project.

The use of goal programming in minimising capacity waste in the Shock Absorber Department of a batch manufacturing automobile plant is illustrated. The concept of capacity waste is outlined and the objectives and constraints of capacity waste minimisation identified. Only linear objectives of the minimisation of idle time, set‐up time, work‐in‐process inventory and maximisation of profit are considered for the development of the goal programming model. The manufacture of different kinds of piston rods for various makes of shock absorbers are described and relevant data pertaining to processing time, setup time, work‐in‐process inventory, etc, are presented. A goal programming model, formulated for the problem, is analysed for different priority structures.

TO say that the Twenty‐fourth S.B.A.C. Show was an unqualified success is perhaps to gild the lily. True there were disappointments— the delay which kept the TSR‐2 on the ground until well after the Show being one—but on the whole the British industry was well pleased with Farnborough week and if future sales could be related to the number of visitors then the order books would be full for many years to come. The total attendance at the Show was well over 400,000—this figure including just under 300,000 members of the public who paid to enter on the last three days of the Show. Those who argued in favour of allowing a two‐year interval between the 1962 Show and this one seem to be fully vindicated, for these attendance figures are an all‐time record. This augurs well for the future for it would appear that potential customers from overseas are still anxious to attend the Farnborough Show, while the public attendance figures indicate that Britain is still air‐minded to a very healthy degree. It is difficult to pick out any one feature or even one aircraft as being really outstanding at Farnborough, but certainly the range of rear‐engined civil jets (HS. 125, BAC One‐Eleven, Trident and VCIQ) served as a re‐minder that British aeronautical engineering prowess is without parallel, while the number of rotorcraft to be seen in the flying display empha‐sized the growing importance of the helicopter in both civil and military operations. As far as the value of Farnborough is concerned, it is certainly a most useful shop window for British aerospace products, and if few new orders are actually received at Farnborough, a very large number are announced— as our ’Orders and Contracts' column on page 332 bears witness. It is not possible to cover every exhibit displayed at the Farnborough Show but the following report describes a wide cross‐section beginning with the exhibits of the major airframe and engine companies.

THE operating economics, basic design philosophy, power plants, and systems, structural and aerodynamic design of the British Aircraft Corporation One‐Eleven short‐range airliner have been dealt with in considerable detail in the preceding five articles. This final article is intended as ‘back‐up’ information—primarily to the systems description by Mr Carline—but whereas the earlier descriptions have concentrated upon general philosophies and the complete systems, it is intended here to describe specific pieces of equipment and the contributions of a number of Companies in support of the BAC One‐Eleven programme.

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.