This paper presents a simple logic-model semantics for Software Cost Reduction (SCR) software requirements. Such a semantics enables model-checking of native SCR requirements and obviates the need to transform the requirements for analysis. The paper also proposes modal-logic abbreviations for expressing conditioned events in temporal-logic formulae. The Symbolic Model Verifier (SMV) is used to verify that an SCR requirements specification enforces desired global requirements, expressed as formulae in the enhanced logic. The properties of a small system (an automobile cruise control system) are verified, including an invariant property that could not be verified previously. The paper concludes with a discussion of how other requirements notations for conditioned-event-driven systems could be similarly checked.

This paper presents a simple logic-model semantics for Software Cost Reduction (SCR) software requirements. Such a semantics enables modelchecking of native SCR requirements and obviates the need to transform the requirements for analysis. The paper also proposes modal-logic abbreviations for expressing conditioned events in temporal-logic formulae. The Symbolic Model Verifier (SMV) is used to verify that an SCR requirements specification enforces desired global requirements, expressed as formulae in the enhanced logic. The properties of a small system (an automobile cruise control system) are verified, including an invariant property that could not be verified previously. The paper concludes with a discussion of how other requirements notations for conditioned-event-driven systems could be similarly checked.

This paper describes the use of computer modelling and simulation during the design and development of a motorized upper limb orthotic system to be used to aid the dysfunctional human arm. The orthosis consisted of a three-degree-of-freedom shoulder module and a lower arm module providing movements at the elbow and wrist. Simulation software has been used to model the mechanism created by the connection of the orthosis and the arm. With this model it has been possible to analyse the kinematics and kinetics of both the arm and orthosis during a variety of dynamic loading conditions. In particular, the power requirements of the orthotic joints during the execution of specific tasks have been determined and these data have been used to specify the motors of a working prototype. The effect of misalignment between real and orthotic shoulder joints has also been investigated and a potentially hazardous situation has been highlighted prior to testing of the prototype by a volunteer in the laboratory.

This paper investigates the effect of specimen geometry and test boundary conditions on the measured dynamic mechanical properties of high strength sheet steel derived from high speed tensile testing at 15m/s, using a servo-hydraulic test machine. In this study, stochastic modelling is used extensively to support experimental investigations. From the results, recommendations are proposed in detail, for an improved specimen design, and hence a robust test procedure, to generate reliable material strain rate sensitivity data for automotive sheet steels at higher strain rates, typically up to 600s-1. The recommendations proposed are expected to have broader application.

The study presented in this paper was carried out to investigate further the effects of strain rate on the strength of adhesively bonded single lap shear joints. Tests were carried out on two different configurations of adhesively bonded joints that were designed to exhibit different behaviours. In one configuration both adherends were made from a relatively low strength grade of aluminium such that both would exhibit significant plastic deformation prior to adhesive failure. The other configuration used one adherend that was significantly stronger such that only elastic deformation was exhibited prior to failure of the adhesive. The joint specimens were tested at several different strain rates using a servo-hydraulic test machine and the results analysed using statistical methods. To further understand the results Finite Element models of the joints were created using a Cohesive Zone Model to predict damage development and failure in the adhesive. The Design of Experiments procedure was used to study the effects of material parameters relating to both the adherends and the adhesive in the Finite Element models. The results of the testing suggested that the strength of joints formed from two adherends that exhibited plastic deformation prior to failure did not show statistically significant sensitivity to strain rate. Interpretation of the results of the Finite Element analyses suggested that the adherend yield was the main factor influencing failure in the adhesive for joints of this type.