This paper describes the implementation of a MATLAB program based on the Object Oriented Programming paradigm for linear‐elastic analysis of one‐dimensional element models using a conventional displacement‐based procedure. The main objective is the development of an educational tool on matrix structural analysis with a didactic and well‐documented open source code, which allows any user to implement new procedures with relative simplicity. The LESM (Linear Elements Structure Model) program can handle different types of analysis models, such as 2D/3D frames and trusses, and grillages. In addition, both Euler‐Bernoulli and Timoshenko theories for bending behavior of beam elements are considered. The OOP class architecture was devised for generically handling these different types of analyses models and element types. The MATLAB script codes of all classes and methods of LESM, including its documentation, are available in its site (http://www.tecgraf.puc-rio.br/lesm).

This paper presents an interactive graphics tool for the structural analysis of one-dimensional element models, such as trusses, frames, and grillages. The focus is on the creation of a graphical user interface for a previously developed analysis solver. This graphical interface is entirely implemented in the MA-TLAB environment and features intuitive resources so that modeling and verification of results become easy tasks for students and engineers. The management of mouse events and the adopted solutions to basic computer graphics issues that arise from interactive modeling in two-dimensional and three-dimensional canvases are discussed, including the strategies to pick objects in spatial coordinates and to identify crossing elements. The result is a new educational software that proved to be a very useful application in structural analysis and introductory computer graphics courses for engineering. The article also presents examples of using the software as an educational tool.

Bladed mixers are widely used for processing granular materials where significant mechanical energy is required to produce the desired blend. Some mechanical energy is dissipated within the granular medium, generating heat during this process. However, our knowledge of the heat generation mechanisms without external thermal loads is still lacking. This study uses an overhead stirrer to mix granular materials and investigate heat generation by monitoring the temperature changes in the granular bed. Additionally, first-order kinetic equations are used to extrapolate the experimental data to a thermal equilibrium where the heat generation and heat loss rates are equal. Lead, steel, and glass particles are used under various operating conditions. It is observed that metallic particles heat up faster owing to their lower heat capacity. Also, increasing the rotation speed, fill ratio and particle size result in a greater temperature increase. Moreover, flat blades induce more heat generation compared to tilted blades.

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