lijfplaat (de lijfplaat van een balk = the web of a beam)
English
web plate (the vertical plate connecting the upper and lower flanges or cover plates of the girder. CMAA Specifications for Electric Overhead Traveling Cranes, 70-7 Glossary[1])
shear web (gegolfde lijfplaat = corrugated shear web; Definition: a shear-carrying member, stiffened by virtue of being corrugated; Definition reference: Multilingual Aeronautical Dictionary (AGARD, 1980))