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Medium-density fiberboard (MDF), comprised of chopped wood fibers and epoxy resin is commonly used in building construction. Given the current trend in freeform architecture, there is a need to generate complex geometric structures out of common construction materials. In this study, kerfing (relief cutting) method is used to create flexible and moldable shapes out of relatively rigid wood panels. The kerf panels can be easily formed into various complex shapes for outdoor facades and/or indoor paneling. The natural wood fibers and epoxy resin in MDF combine to produce a viscoelastic composite material that exhibits time-dependent changes in mechanical behavior, i.e., material stiffness/compliance. The work described herein comes from a study designed to develop a better understanding of the viscoelastic response of kerf unit cells and panels. Experimental creep tests were performed on dog-bone specimens under uniaxial loading conditions1in order to determine the viscoelastic response of the MDF. The experimental results were used to develop a model to be used in simulations. The simulations were carried out on a kerf unit cell, e.g., a square interlocked kerf, and kerf structures of complex geometries in order to investigate the time-dependent changes in the deformations of the kerf structures. From this study, a systematic design of kerf panels with complex shapes will be developed in order to minimize the time-dependent changes of kerf structures.

The aim of this paper is to describe a new MS Excel‐based approach for designing driveshafts for stiffness and fatigue strength. We analyze the efficacy of the approach in engaging students in an iterative design process and higher‐level qualitative decision‐making activities in an undergraduate class at Texas A&M University. Compared to conventional fixed cross‐section frames and trusses, there are few tools (barring Finite Element Packages) that facilitate rapid design evaluations of stepped shafts. The approach is based on a novel use of singularity functions to obtain explicit solutions for stepped shafts under concentrated loads. This approach allows for relatively easy implementation into Excel without the need for any numerical integration or other forms of approximation. Currently, the tedious calculations involved in the design of stepped shafts prevent instructors from exploring iterative changes in driveshaft design. The Excel tool that we have developed allows instructors and students to focus on iterative decision‐making. With this tool, open‐ended design questions are assigned even in exams since the entire iterative process takes less than 15–20 min. Student surveys and analysis of exam answers reveal that students have gained a considerable capability to make design decisions. They also indicate areas where improvement in design thinking is needed.