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Basic Rules of Engineering Design. Safe Simple Clear. Interrelationship Between the Safety Levels. Definition: Safety. Safety is a state in which the risk is smaller than the risk limit Risk limit
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Basic Rules of Engineering Design • Safe • Simple • Clear
Definition: Safety Safety • is a state in which the risk is smaller than the risk limit Risk limit • is the largest still acceptable system-specific risk relating to a particular technical process or situation Protection • is the reduction of risk by suitable means to reduce the frequency of the occurrence or the extent of damage or both
Aspects of Safety Technology • Self-protection: product liability • EC machinery directive : DIN EN 292; VDE 100; VDI 2244 • CE-Certification: declaration of conformity • ISO 9001: document management; modification management; version management
Aspects of Safety Technology Market acceptance: • safe and environment-friendly products are received better by the market • customers are prepared to pay more for safer products • safety leads to a positive brand image: Mercedes, Volvo, Saab….
Safe-Life Important Measures: • Over-dimensioning of parts • Clear and simple embodiment design • Field-tests for determining the actual loads • Employ experienced interdisciplinary teams for the development • Documented quality assurance over the complete life-cycle • Inspection/maintenance
Aspects of Warning Safety Technology • Lowest level of safety technology supplementary to other measures • minimum measure when no other safety principle is applicable • consider aspects of noticability and ergonomics
Aspects Concerning Safety Data Sheets • safety data sheets describe the danger potential of materials and substances • the danger potential of materials and substances must be considered over the complete life cycle of a product: • - production • - commissioning • - operation • safety data sheets are a part of the product documentation
Material Aspect of Safety Technology • The safety of a product can be increased by choosing a material that suits the operating conditions of the product • Determining the operating conditions is crucial for the choice of materials: • - corrosion resistant materials • - fatigue resistant materials • - materials that have a good adhesion to lubricants
Aim of Principles of Embodiment Design • The application of principles of embodi-ment design leads to products that are optimally designed – regarding the requirements taken into account!
Direct and Short Force Transmission • Flowlines of force must always be closed • Force transmission must be as short as possible Avoid: • deflection of forces • discontinuous change of cross-section • change of density of force flowlines
Direct and short force transmission Idea of force transmission Definition:The basic idea and illustration of force and moment transmission is taken from the field of fluid mechanicsSource:
Direct and short force transmission Fundamentals: • The flowlines of force should always be closed. (Inertial forces are not taken in to consideration) • The stresses and strains change with in circular flowlinesof force. • The flowlinesof force searches the shortest path • The flowlinesof force come closer in narrow cross sectional areas.-On the other hand, they expand in broad cross sectional areas
Principle of Balanced Forces • Target: • Reached by: system is free of forces to the outside • symmetric structure of the system regarding the flow of forces