Systematic design optimization of grabs considering bulk cargo variability

M. Javad Mohajeri*, Arjan J. van den Bergh, Jovana Jovanova, Dingena L. Schott

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

8 Citations (Scopus)
164 Downloads (Pure)


Ship unloader grabs are usually designed using the manufacturer's in-house knowledge based on a traditional physical prototyping approach. The grab performance depends greatly on the properties of the bulk material being handled. By considering the bulk cargo variability in the design process, the grab performance can be improved significantly. A multi-objective simulation-based optimization framework is therefore established to include bulk cargo variability in the design process of grabs. The primary objective is to reach a maximized and consistent performance in handling a variety of iron ore cargoes. First, a range of bulk materials is created by varying levels of cohesive forces and plasticity in the elasto-plastic adhesive DEM contact model. The sensitivity analysis of the grabbing process to the bulk variability allowed three classes of iron ore materials to be selected that have significant influence on the product performance. Second, 25 different grab designs are generated using a random sampling method, Latin Hypercube Design, to be assessed as to their handling of the three classes of iron ore materials. Of this range of grab designs, optimal solutions are found using surrogate modelling-based optimization and the NSGA-II genetic algorithm. The optimization outcome is verified by comparing predictions of the optimization algorithm and results of DEM-MBD co-simulation. The established optimization framework offers a straightforward and reliable tool for designing grabs and other similar equipment.

Original languageEnglish
Pages (from-to)1723-1734
JournalAdvanced Powder Technology
Issue number5
Publication statusPublished - 2021


  • Cohesive iron ore
  • DEM-MBD co-simulation
  • Grabs
  • Multi-objective optimization
  • Sustainable design


Dive into the research topics of 'Systematic design optimization of grabs considering bulk cargo variability'. Together they form a unique fingerprint.

Cite this