The present work was developed with the objective of investigating the characteristics of bending of the wood of Sycamore (Platanus x acerifolia), açoita-cavalo (Luehea divaricata), and pecan (Carya illinoinensis) coming from forests non managed for this end from the area of the Depressão Central and Encosta Superior do Nordeste of the state Rio Grande do Sul/Brasil. There were cut down five representative trees of each species and study area. There were determined the characteristics such as log as taper and idiosyncrasy. In the study there was defined the year of segregation of juvenile/adult wood by means of the radial variation of anatomical characteristics and basic density. The wood was bent in rays of 16 and 21 cm, with wood initial moisture of 14%, and after water boiling for 35 minutes. For the qualification of the defects of the bending wood, the methodology described by Vorreiter (1958) was followed. The most probable year of segregation is the defined by the radial variation of fiber length that was determined, respectively as, 21, 16 and 14 years for açoita-cavalo, pecan and sycamore. With relationship to the quality of the wood bending, the juvenile wood was surprisingly better than the adult wood for the rays and tested species. In this resard, there are not great needs of a forest handling that decreases the amount of juvenile wood. Nevertheless, trunk breakdown should be made respecting the direction of the fibers; thus, avoiding the main defect of the wood bending (splintering by tension). The best results of the bending wood were observed for the wood of pecan. Possibly, the ring porous wood, characteristic of the species, contributed in the result. Meanwhile, açoita-cavalo and sycamore, wood with diffuse porosity and of high parenchyma proportion, presented a great amount of defective pieces. / O presente trabalho foi desenvolvido com o objetivo de investigar as características do vergamento da madeira de plátano (Platanus x acerifolia), açoita-cavalo (Luehea divaricata) e nogueira-pecã (Carya illinoinensis) procedentes de florestas não-manejadas para este fim das regiões da Depressão Central e Encosta Superior do Nordeste do estado do Rio Grande do Sul/Brasil. Foram abatidas cinco árvores adultas representativas de cada espécie e Região de estudo, das quais foram determinadas as características da forma do tronco como conicidade e índice de circularidade. No estudo definiu-se o ano de segregação dos lenhos juvenil/adulto por meio da variação radial de características anatômicas e de massa específica básica. As madeiras das espécies testadas foram vergadas em raios de 16 e 21 cm, com teor de umidade inicial de aproximadamente 14%, após cozimento em água fervente por 35 minutos. Para a qualificação dos defeitos de vergamento, foi seguida metodologia descrita por Vorreiter (1958). Os principais resultados indicam que o ano de segregação mais provável é o definido pela variação radial do comprimento da fibra que foi, respectivamente, 21, 16 e 14 anos para açoita-cavalo, nogueira-pecã e plátano. Quanto à qualidade do vergamento, os corpos-deprova do lenho juvenil vergaram surpreendentemente melhor que os corpos-de-prova do lenho adulto para os raios e espécies testadas. Dessa forma, não há grandes necessidades de um manejo florestal que diminua a quantidade de lenho juvenil. No entanto, o desdobro das toras deve ser feito respeitando a direção das fibras, assim evitando o principal defeito do vergamento observado (estilhaço). Na madeira de nogueira-pecã, foram observados os melhores resultados do vergamento independentemente do raio. Aparentemente, a porosidade em anel, característica da espécie, contribuiu para o resultado. Já as madeiras de açoita-cavalo e plátano, com porosidade difusa e com grande proporção de parênquima, apresentaram uma grande quantidade de peças defeituosas.

In der vorliegenden Arbeit werden Holzwerkstoffe im statischen Biegeversuch und im Schlagbiegeversuch vergleichend geprüft. Ausgewählte Holzwerkstoffe werden thermisch geschädigt, zudem wird eine relevante Kerbgeometrie geprüft. Ziel der Untersuchungen ist die Eignung verschiedenartiger Werkstoffe für den Einsatz in sicherheitsrelevanten Anwendungen mit Schlagbelastungen zu prüfen. Hierzu werden zunächst die Grundlagen der instrumentierten Schlagprüfung und der Holzwerkstoffe erarbeitet. Der Stand der Technik wird dargelegt und bereits durchgeführte Studien werden analysiert. Darauf aufbauend wird eine eigene Prüfeinrichtung zur zeitlich hoch aufgelösten Kraft-Beschleunigungs-Messung beim Schlagversuch entwickelt. Diese wird anhand verschiedener Methoden auf ihre Eignung und die Messwerte auf Plausibilität geprüft. Darüber hinaus wird ein statistisches Verfahren zur Überprüfung auf ausreichende Stichprobengröße entwickelt und auf die durchgeführten Messungen angewendet. Anhand der unter statischer und schlagartiger Biegebeanspruchung ermittelten charakteristischen Größen, wird ein Klassenmodell zum Werkstoffvergleich und zur Werkstoffauswahl vorgeschlagen. Dieses umfasst integral die mechanische Leistungsfähigkeit der geprüften Holzwerkstoffe und ist für weitere Holzwerkstoffe anwendbar. Abschließend wird, aufbauend auf den gewonnenen Erkenntnissen, ein Konzept für die Bauteilprüfung unter Schlagbelastung für weiterführende Untersuchungen vorgeschlagen. / In the present work wood-based materials are compared under static bending load and impact bending load. Several thermal stress conditions are applied to selected materials, furthermore one relevant notch geometry is tested. The objective of these tests is to investigate the suitability of distinct wood materials for security relevant applications with the occurrence of impact loads. For this purpose the basics of instrumented impact testing and wood-based materials are acquired. The state of the technology and a comprehensive analysis of original studies are subsequently presented. On this basis an own impact pendulum was developed to allow force-acceleration measurement with high sample rates. The apparatus is validated by several methods and the achieved signals are tested for plausibility. A general approach of testing for adequate sample size is implemented and applied to the tested samples. Based on the characteristic values of the static bending and impact bending tests a classification model for material selection and comparison is proposed. The classification model is an integral approach for mechanical performance assessment of wood-based materials. In conclusion a method for impact testing of components (in future studies) is introduced.