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Non-destructive techniques for characterizing materials in-service have been increasing in importance. Thus, it is relevant to assess the potential of non-destructive techniques for solid materials. This work aimed to determine the modulus of elasticity of Bertholletia excelsa wood using the particle image velocimetry technique and the ultrasound method to compare the results with the conventional methodology. For this purpose, samples of Bertholletia excelsa were made using a circular saw. The samples were evaluated for sound propagation to calculate the modulus of elasticity using ultrasound equipment. Subsequently, they were subjected to the compression parallel to grain test in a universal testing machine. The samples were marked and monitored during the loading session, with the repeated capture of images using a professional camera. The deformation values obtained were used to estimate the modulus of elasticity using the particle image velocimetry technique. The mean values of modulus of elasticity found were 17403 MPa for ultrasound, 15589 MPa for the particle image velocimetry technique, and 15333 MPa for the universal testing machine. The particle image velocimetry technique was considered to be statistically similar (Tukey α = 0,05) to the other methods tested. The linear coefficient of determination (R2) between the particle image velocimetry technique and the universal testing machine was 0,95, a high and satisfactory value. Thus, the particle image velocimetry technique and the ultrasound method are valid to estimate the modulus of elasticity of Bertholletia excelsa wood and possibly of woods with similar technological characteristics.

Several non-destructive testing techniques have been improved and tested in recent years. The non-destructive testing techniques using particle image velocimetry (PIV) and digital image correlation (DIC) differ from conventional testing techniques, as they allow making measurements indirectly. In this study, the elastic modulus in wood beams of Eucalyptus grandis and Pinus oocarpa were determined using PIV and DIC. The application of PIV and DIC techniques occurred during the static bending tests, when the displacements were also measured by the conventional method. The applied load values allowed calculating the elasticity modulus. In all regions of analysis, the mean values of the elasticity modulus found by the DIC, PIV and conventional method are statistically equivalent. It is concluded that the PIV and DIC testing techniques can be used to determine mechanical properties of wood.

espanolEn este trabajo se valora la eficiencia de una resina de pino modificada biodegradable (A-30), al utilizarla como compatibilizante o acoplante para sustituir al resorcinol (que es toxico y no es biodegradable), comparando las propiedades mecanicas (contra formulaciones preparadas usando el sistema resorcinol-hexametilentetramina (R-HMT) en: a) polimeros elastomericos reticulados de estireno-butadieno (SBR), y: b) compositos de SBR reforzados con fibra de agave de desecho. Para la comparacion como compatibilizante, aqui se preparan formulaciones equivalentes con A-30 o R-HMT. Para la comparacion de los compositos equivalentes, se varia el agente de acoplamiento (R-HMT o A-30) y la cantidad de azufre como agente de entrecruzamiento (2,5 partes por cien de elastomero (phr), 7,5 phr o 15 phr). En las pruebas de traccion a temperatura ambiente, y el analisis mecanodinamico con barridos de temperatura (de - 70 °C a 40 °C) y frecuencia (de 0,4 Hz a 40 Hz), se obtuvieron incrementos en modulos (hasta un 74 % en modulo de Young) y en capacidad de deformacion (hasta 260 %), para los materiales conteniendo el agente A-30, por encima de las formulaciones en las que se uso el resorcinol. El mejor desempeno como compatibilizante o acoplante del A-30, se reflejo tambien con claridad morfologicamente mediante microscopia electronica de barrido, al mostrar mayor compacidad en la matriz formulada y mayor cercania entre fibra y matriz en muestras fracturadas criogenicamente. Se ha demostrado aqui, que el A-30 puede sustituir al par R-HMT con exito, ya que funciona mejor como agente compatibilizante o acoplante y es biodegradable. Este tipo de agentes tiene un gran potencial para contribuir al desarrollo de elastomeros y compositos flexibles amigables con el medio ambiente EnglishIn this work, the effectiveness of a biodegradable modified pine rosin (Amberyl MP-30 (A-30)), is evaluated as compatibilizer or coupling agent to substituteresorcinol (which is toxic and non-biodegradable) in elastomeric formulations. Their mechanical properties are compared vs formulations containing resorcinol-hexamethylenetetramine (R-HMT) in: a) styrene–butadiene elastomers (SBRs), and: b) SBR composites reinforced with discarded agave fibers. For the comparison as compatibilizer, equivalent formulations containing resorcinol or A-30 are prepared. Likewise, for the equivalent composites comparison, the coupling agent (R-HMT or A-30) and sulfur amount as crosslinking agent (2,5 parts per 100 rubber (phr), 7,5 phr or 15 parts per 100 phr) are varied. The Tensile tests at room temperature, and the mechanodynamic analysis using sweeps of temperature (from - 70 °C to 40 °C) and frequency (from 0,4 Hz to 40 Hz), allowed the observation of moduli improvements (up to 74 % in Young modulus) and deformation capacity (up to 260 %) for the materials with A-30 over the materials where resorcinol was used. The better performance as compatibilizer or coupling agent of the A-30 was also shown with clarity in the morphological characterization, showing higher compacity in the formulated polymer matrix, and higher closeness between matrix and fibers, comparing with fractured samples using R-HMT. It has been shown here, that formulating rubbers or elastomeric composites with A-30 and HMT, can successfully substitute the R-HMT pair, because it works better as compatibilizer or coupling agent and is biodegradable. Agents of natural origin like this one, have a great potential to contribute to the development of elastomers and flexible composites that are environmentally friendly

Throughout their useful life structures demand monitoring to verify their conditions of use. Thus, the need arises to seek methodologies capable to evaluate displacements and deformations in structural components of buildings. The objective of this research was to evaluate the use of the particle image velocimetry (PIV) technique to analyze test specimen behavior during a static bending test, additionally a displacement map is presented. The PIV technique measures variations of position of a region in an object from consecutive images from a loading session. The tests were performed on wood of Pinus oocarpa and Eucalyptus grandis, plywood panels, laminated veneer lumber (LVL) and oriented strand board (OSB). The results obtained by the PIV technique were compared to values obtained from dial indicators. It was verified that in all the materials tested, the PIV technique presented results similar to those found in the dial indicators. By means of the Student t test, with a significance level of 1%, some regions of analysis the values found by the PIV technique and the dial indicators were statistically similar. For the analyzed regions that did not achieve statistical equality, a correction equation was calculated (R² higher than 0.99). It was concluded that the PIV technique, with properly adjusted setup, presented results similar to those obtained in the conventional tests, proving its accuracy and reliability in displacement measurements, with the advantage of being a non-destructive and contactless structure monitoring technique.

The most important parameter in terms of material mechanical behavior knowledge is the modulus of elasticity, being traditionally obtained through destructive tests. The objective of this study is the verification of the potential use of the particle image velocimetry technique (PIV) as a tool to obtain the modulus of elasticity in sawed wood samples (Pinus oocarpa and Eucaliptus grandis) and wood panels (Plywood, LVL and OSB). The PIV technique has as characteristics the low cost of equipment, fast results, no need for contact with the object tested, accuracy and possibility of application in the field. The application of the PIV technique occurred during the static bending tests where the deformations were also measured with a dial indicator (conventional method), thus obtaining comparative measurements. From the load values applied by a universal test machine and deformation values obtained by the dial indicator and PIV techniques, it was possible to calculate the modulus of elasticity through both methods. With the “Student's t” statistical test application with significance level of 1%, it was verified that the modulus of elasticity found by the PIV technique and the dial indicator were statistically equal. Average values for the modulus of elasticity found were respectively for the use of the conventional method and for the PIV method the values of: 13,077 and 13,027 MPA for Eucalyptus grandis; 6,171.6 and 6,418.8 MPa for Pinus oocarpa; 10,481.2 and 11,094.3 MPa for plywood; 8,687.4 and 10,261.0 MPa for the LVL; and 2,480.1 and 2,899 MPa for the OSB. It was concluded that the PIV technique is capable of measuring modulus of elasticity values with similar precision to the test techniques traditionally used for this purpose.

Proposing technological innovations in the investigation of the structure and behaviour of wood is important to optimize its use. The assimilation of methods diffused in other areas, such as particle image velocimetry (PIV), can allow a rich range of information for different aspects. The aim of this study was to estimate the Young’s modulus using the PIV technique, independently of the wood density. The Young modulus value was obtained by universal testing machine, transversal vibration and PIV technique. Cedrela spp. and Eucalyptus cloeziana wood specimens were analyzed and their Young modulus were compared and correlated. The PIV technique presented mean Young’s modulus values statistically equal to those of the universal testing machine. The standard error of prediction from PIV approach was 0.46 and 0.97 GPa for Young’s modulus estimates for Cedrela spp. and Eucalyptus cloeziana wood, respectively.

The Glass Fiber Reinforced Polymer (GFRP) waste despite having excellent physical and mechanical properties is still largely unexplored besides presenting large volume of waste with very low degradability. The use of concrete block presents high resistance to compression, low price high masonry coating ratio by material weight, however high thermal conductivity. Therefore, the study aimed to produce and investigate the effect of adding GRFP residues to concrete blocks due to physical, mechanical and thermal properties. The compositions were made by replacing the fine gravel between 0 to 10% in mass by the GFRP residue. They were evaluated from physical, mechanical and thermal tests. The results showed that the use of GFRP residue did not interfere in water absorption and compressive strength, despite the significant increase in mechanical energy absorption of the material. Thermal conductivity reduced by 46% and the concrete blocks were 7% lighter. In addition to providing a destination for a considerable quantity of the waste, the commercial value of the final product is higher due to using a residue with low degradability and high energy power due to burning during recycling. Los residuos de polímero reforzado con fibra de vidrio (GFRP), a pesar de tener excelentes propiedades físicas y mecánicas, aún están en gran parte inexplorados, además de presentar un gran volumen de residuos con muy baja degradabilidad. El uso de bloques de hormigón presenta alta resistencia a la compresión, bajo precio, alta relación de revestimiento de mampostería por peso del material, sin embargo alta conductividad térmica. Por lo tanto, el objetivo de este trabajo era utilizar los residuos de PRFV en la producción de bloques de hormigón. Las composiciones se prepararon reemplazando la grava fina entre el 0 y el 10% en masa por el residuo de GFRP. Fueron evaluados a partir de pruebas físicas, mecánicas y térmicas. Los resultados mostraron que el uso de residuos de GFRP no interfirió en la absorción de agua y la resistencia a la compresión, a pesar del aumento significativo en la absorción de energía mecánica del material. La conductividad térmica se redujo en un 46% y los bloques de hormigón fueron un 7% más ligeros. Además de proporcionar un destino para una cantidad considerable de residuos, el valor comercial del producto final es mayor debido al uso de un residuo de baja degradabilidad y alto poder energético debido a la quema durante el reciclaje. O resíduo de Polímero Reforçado com Fibra de Vidro (PRFV) apesar de possuir excelentes propriedades físicas e mecânicas ainda é pouco explorado além de apresentar grande volume de resíduo com baixíssima degradabilidade. O uso de bloco de concreto tem alta resistência à compressão, baixo preço e elevada relação do revestimento de alvenaria pelo peso do material, porém alta condutividade térmica. Portanto, este trabalho foi realizado objetivando-se utilizar os resíduos da PRFV na produção de blocos de concreto. As composições foram feitas substituindo o cascalho fino entre 0 a 10% em massa pelo resíduo de PRFV. Eles foram avaliados a partir de testes físicos, mecânicos e térmicos. Os resultados mostraram que a utilização do resíduo de PRFV não interferiu na absorção de água e na resistência à compressão, apesar do aumento significativo na absorção de energia mecânica do material. A condutividade térmica foi reduzida em 46% e os blocos de concreto ficaram 7% mais leves. Além de dar destinação a uma quantidade considerável de resíduos, o valor comercial do produto final é maior devido à utilização de um resíduo de baixa degradabilidade e alto poder energético devido à queima durante a reciclagem.

The knowledge of physics characteristic to grain coffee would allow the transition of the conventional storage model to grain store and as an indirect measure of improving and preserving the quality of stored grain. In this context, this work was realized with the intention of know the elasticity modulus of bulk grains of coffee by the method of non-destructive testing Stress Wave Timer. Thus a silo model was built to reproducing the conditions of storage, and the values ​​of the elastic modulus measured. The values obtained with the Stress Wave Timer are among 2,54 to 4,23 MPa, and maximum load applied was 8.32 kN and vertical pressure was calculated in 1,526 kPa. To assess the impact of storage conditions, laboratory tests, applied to seeds were performed.