Seismic and stability analysis of component-based extraterrestrial vaults

For the first time since the 1970s, concrete plans are in motion to bring humans back to the Moon through the Artemis programme. The dawning era of space exploration aims to set the groundwork for long-term off-Earth settlement, with sights on bringing the first humans to Mars. In order to provide a safe means of inhabiting extraterrestrial (ET)...

Design of a hybrid grab mechanism: enlarging the minimum bulk unloading capacity by torque addition

Grabs are essential in the process of unloading a bulk carrier by grabbing bulk material such as iron ore from the cargo hold. Due to varying operational conditions, the consistency and the amount of payload can vary significantly. One of the largest varying operational conditions is the occurrence of irregular bulk surfaces. Therefore, it is...

Design of grabs for coarse material: Enhancing the penetration and cutting depth for limestone

Due to the constant growth of global maritime shipping, the optimization of grabs used for unloading bulk carriers is more and more relevant. Especially for a coarse material like limestone, the average payload can be improved, by altering the grab design. It is suggested that the penetration and cutting depth of a grab can be improved, which...

粉末床熔融的多材料铺粉过程中粉末扩散的数值研究

Powder bed fusion additive manufacturing has been applied to the fabrication of functionally graded materials. A new design that allows the material composition to change along the direction perpendicular to the powder spreading has been reported in the literature. Based on this design, this work examines the quality of the graded spread...

Numerical investigation of plastic fragment accumulation against a sluice gate

The ramifications of plastic pollution on the environment are becoming increasingly serious in various forms throughout the world. In this context, rivers are the most important suppliers of plastics entering the marine environment. However, rivers that contain high loads of plastic waste also directly harm the livelihoods of people living near...

Simulating monopile installation through scour protection using the Discrete Element Method

Over 5000 offshore wind turbine generators have been installed in the past decades. 80% of these wind turbines have a monopile foundation. Monopiles are hollow steel tubular piles with a diameter of up to 10m. The first phase of the monopile installation consists of the self-weight penetration into the seabed due to the mass of the monopile....

The increase of grab lifetime through wear management

Bulk handling grabs wear due to interaction with bulk material. In this research the geometrical shape of the grab is adjusted to reduce this wear. A DEM simulation using an iron ore pellet material model, created by S. Lommen, is used to assess different concepts. The material model is validated for forces, but not for wear. Wear measurements...