Rural roads and bridges are fundamental to outflow agricultural products and promoting the local population mobility. In rural areas or forests, with scarce construction resources, are common to design bridges using wood in order to reduce the demanded energy to produce then. That kind of infrastructure systems, present low structural stiffness, durability and reliability, due the wood inherent mechanical properties variability and hygroscopicity. In this way, the inspection, monitoring and maintenance programs become extremely important. The Structural Health Monitoring (SHM) techniques can be employed to solve these issues. However, depending on the structure size, location and number of monitoring points, the monitoring process becomes considerably costly, especially if the bridges is located difficult access, such as forests. Therefore, as a management tool, the use of low-cost monitoring systems can be an alternative for the implementation of maintenance programs for this type of structure, in more distant rural areas. The present research was developed with the objective of proposing, developing and evaluating a low-cost data acquisition system for SHM to be applied in bridges on rural roads or forest areas. The low-cost data acquisition system for SHM of bridges was developed and subsequently validated in the laboratory and posteriorly under field conditions. As an important conclusion, the proposed low-cost system can be indicated for the establishment of maintenance programs, as well as being used for the implementation of conservation programs and management support, considering the applicability and limitation observed in the present research.

The use of computational simulation techniques is an important tool for the coffee harvesting issues, particularly the finite element method. The method is widely used in the structural analysis of agricultural machinery, as well as in the analysis of the stresses and vibrations of coffee branches and peduncles during the harvesting process. The present study aimed to develop three-dimensional finite element models of the plagiotropic branches of the Catuaí Vermelho variety of Arabica coffee in different positions along the orthotropic branches of the plant; considering high-fidelity models. Additionally, by considering the branches’ experimental properties (physical-mechanical), the natural frequencies and vibration modes of the branches were determined by means of computer simulations. First, the geometric properties of the coffee branches were obtained by means of two images taken using a professional camera to obtain the input data of the virtual simulation. For the mechanical properties, it was used a semi-analytical digital scale, to obtain the mass of the specimens. The modulus of elasticity was determined using a universal testing machine. The variability in the simulated natural frequencies could be identified, which was on the order of 30% for the first frequency, regardless of the position of the branch in the plant. These values were lower for the other frequencies. Linear regression fits showed a coefficient of determination, and correlation tests were used to verify the relationship between the values obtained numerically and experimentally, which were validated by using experimental data using the modal analysis techniques.