SUPERVISOR: Benjamin KROMOSER

PROJECT ASSIGNED TO: Ahmadreza Ghazanfari

The ongoing reduction in quantity and quality of forest-derived wood resources has intensified the quest for alternative materials to supplant solid wood. This research led to the invention of strand-based materials, initiating with Oriented Strand Board (OSB), which was developed as a substitute for plywood and other solid wood materials and expanded over time to other strand-based engineered wood products (EWPs) such as structural composite lumbers (SCLs) family. These materials not only demonstrate enhanced resource efficiency but also show superior mechanical properties when compared to other wood composites.

The "Unistrand" project's primary goal is to explore the potential of a Engineered Wood Product (EWP), termed Unidirectional Strand Board (USB), which parallels OSB in its usage as a board element. However, USB is composed of a single layer, with all wood strands oriented longitudinally, similiar to Laminated Strand Lumber (LSL). The project will also delve into various layup configurations and grading of USB to enhance its suitability for a broad range of applications, particularly in multi-story building construction and diverse structural projects. This exploration aims to broaden the scope and efficiency of this material in future construction endeavors.

The objective of this thesis is to validate the appropriateness and safety of this material from structural design aspects, focusing on three critical stages as depicted in figure 1. Initially, a variety of mechanical tests will be carried out to determine key stiffness and strength characteristics under various loading scenarios, including compression, tension, shear, and bending (Figure 1.1). The data gathered from this stage will be used as input for the second phase, which involves material modeling in a finite element analysis using advanced software such as Abaqus. This phase aims to replicate the material’s response to stress, exploring potential failure modes, displacements, and material characteristics. Furthermore, the developed model will be cross-referenced with experimental results to verify its precision (Figure 1.2). The final phase involves the structural design of this material employing a semi-probabilistic approach, ensuring its safety and effectiveness for diverse structural applications (Figure 1.3).
 

Figure 1. Graphical abstract of the dissertation