S23  Projeto de Sistemas Mecânicos    Titulo: ESTUDO COMPARATIVO DA ESTABILIDADE DIRECIONAL DE DUAS COMBINAÇÕES VEICULARES TIPO CAVALO SEMI-REBOQUE   Resumo : COMPARATIVE STUDY OF THE DIRECTIONAL STABILITY OF TWO VEHICLE COMBINATIONS TRUCK SEMI-TRAILER TYPE. ABSTRACT. STUDY OF THE DIRECTIONAL STABILITY OF TWO VEHICLE COMBINATIONS TRUCK SEMI-TRAILER TYPE USING THE “CENTRE OF GRAVITY RANGE” TECHNIQUE. IT IS SHOWN THE AREA WITHIN WHICH THE CENTRE OF GRAVITY OF EACH VEHICLE UNIT MUST BE LOCATE IN ORDER TO RESPECT THE LIMITS OF LOAD THAT THE MANUFACTURER AND THE LEGISLATION IMPOSE. EACH POSITION OF THE C.G. IS CONSIDERED AS ONE OF THE POSSIBLE FORMS OF LOADING THE VEHICLE BY THE USER. FOR SOME OF THE MAIN POSITIONS OF THE CENTRE OF GRAVITY CURVES ARE OBTAINED THAT REPRESENT THE CHARACTERISTIC RESPONSE MOVEMENTS OF THE COMBINATION (WITH THEIR DAMPING RATIO) IN THE FACE OF AN EXTERNAL INTERFERENCE. THE PROCEDURE PERMITS THE COMPARISON OF VEHICLES IN RELATION TO THEIR DYNAMIC PERFORMANCE IN STABILITY WITH THE OBJECTIVE OF GIVING JUSTIFIED ANSWER TO THE EXISTENT POLEMIC IN BRAZIL WITH REFERENCE TO WHICH OF THE TWO VEHICLE COMBINATIONS IS MORE STABLE AND SAFE: THE TWO AXLES TRACTOR WITH A SEMI-TRAILER OF THREE AXLES OR THE THREE AXLES TRACTOR WITH A SEMI-TRAILER OF TWO AXLES. THE STUDY SHOWS THAT THE FIRST COMBINATION, BEING THE CONFIGURATION MORE USED IN BRAZIL, IS LESS STABLE, AND THAT THEIR WIDE USE IS BASED ON MAINLY ECONOMIC RATHER THAN TECHNICAL REASONS. THE STUDY MEANS TO INDICATE WAYS TO INCREASE VEHICULAR SAFETY ON THE HIGHWAYS AND MAKE POSSIBLE THE MOST RATIONAL AND SAFE USE OF THE EQUIPMENT. KEY WORDS. ARTICULATED VEHICLES, TRACTOR SEMI-TRAILER, VEHICLE DYNAMICS, VEHICLE STABILITY, HEAVY VEHICLES.     Autores : Canale, Antônio Carlos 0 Horta Gutiérrez, Juan Carlos 0     Trabalho Completo :   COBEM99 | Comissão  Organizadora | Palestras | Sessões Técnicas | Autor | Simpósios e Sessões Especiais | Revisores |  Título  dos  Trabalhos | Local