Maximizing ollie height by optimizing control strategy and skateboard geometry using direct collocation

The ollie is the base aerial human–board maneuver, foundational to most modern skateboarding tricks. We formulate and solve an optimal control problem of a two-dimensional simplified human model and a rigid body skateboard with the objective of maximizing the height of the ollie. Our solution simultaneously discovers realistic human-applied...

Early detection of impact fatigue damage in an adhesively-bonded connection using acoustic emission

Wind turbine blades carry the risk of impact damage during transportation, installation, and operation. Such impacts can cause levels of damage that can propagate throughout the structure compromising performance and safety. In this study, the effect of impact damage on fatigue damage propagation in test specimens representative of a spar cap...

Delamination link-ups in composite laminates due to multiple hail impacts

Damages to aircraft fuselages by ice impactors are categorized as barely visible impact damage (BVID). As the application of composite laminates in manufacturing aircraft fuselage is increasing rapidly, studying hail impact on composite laminates seems crucial. Investigation of variation of delamination area and link-up area for different...

Extreme shearography: Development of a high-speed shearography instrument for quantitative surface strain measurements during an impact event

Monitoring of extreme dynamic loadings on composite materials with high temporal and spatial resolution provides an important insight into the understanding of the material behaviour. Quantitative measurement of the surface strain at the first moments of the impact event may reveal the initiation of the failure mechanisms leading to damage....

Bondline thickness effects on damage tolerance of adhesive joints subjected to localized impact damages: Application to leading edge of wind turbine blades

The leading edges of wind turbine blades are adhesively bonded composite sections that are susceptible to impact loads during offshore installation. The impact loads can cause localized damages at the leading edges that necessitate damage tolerance assessment. However, owing to the complex material combinations together with varying bondline...

Dynamic crushing behavior of closed-cell aluminum foams based on different space-filling unit cells

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Impact behavior of model porous concretes

In this work, findings of a numerical study performed to investigate the impact behavior of porous concrete, modeled as a four phase cementitious composite consisting of aggregates, cement paste, interfacial transition zones (ITZ) and air, are presented. The numerical analyses contributed to the process of designing a special type of concrete...

Advancing Industry through Design: A Longitudinal Case Study of the Aviation Industry

Design educators and industry partners are critical knowledge managers and co-drivers of change, and design graduate and post-graduate students can act as catalysts for new ideas, energy, and perspectives. In this article, we will explore how design advances industry development through the lens of a longitudinal inquiry into activities...

Ballistic model for the prediction of penetration depth and residual velocity in adobe: A new interpretation of the ballistic resistance of earthen masonry

In this paper, a new one-dimensional phenomenological model is developed for the assessment of the ballistic performance of Adobe. Adobe is a masonry largely spread in areas of the world involved in military operations. Addressing fundamental ballistic parameters such as residual velocity or penetration depth for this building technology is...

Breakage of sodium benzoate granules under repeated impact conditions

Breakage behaviour of enzyme granules in a repeated impact test