End cover is getting bend by Allen socket round head bolt

[COLOR=#3E3E3E]Hello everyone,[/COLOR]

[COLOR=#3E3E3E]We are hydraulic cylinder manufacturer, currently we are working on a cylinder which end cover is getting bend due to less wall thickness which is 8mm. we have a big lot of these end covers we will be on big loss if this mistake not addressed.[/COLOR]
[COLOR=#3E3E3E]Kindly suggest some alternatives/solutions pls go through the attached pictures for better clarity. [/COLOR]

[COLOR=#3E3E3E]Important parameters:[/COLOR]

[COLOR=#3E3E3E]Load on each bolt: 1.7 tonn[/COLOR]
[COLOR=#3E3E3E]Hydraulic cylinder size: Ø80 x Ø45 x 115 Stroke[/COLOR]

[URL="https://www.engineersedge.com/engineering-forum/attachment.php?attachmentid=2084&d=1516454929"]Cylinder pic 1.jpg[/URL]

[COLOR=#3E3E3E]Pls ask if more information required[/COLOR]

[COLOR=#3E3E3E]Thanks[/COLOR]
[COLOR=#3E3E3E]Amit[/COLOR]

Honestly, the end cap should be redesigned thicker to with stand the applied forces. You could also derate the hydraulic cylinder to a force that will not yield the end plate.

Regardless of what choice the endcaps, stud/bolts and all other critical parts should be analyzed for structural integrity.

I didn't see anything here that could not have been predicted with some good analysis. I find it hard to believe a competent cylinder manufacturer did not do that. I don't think there is any way to save the existing plates, unless you change the strength requirements. On the next design you might consider replacing the milled flats for the bolt heads with counterbored holes, so at least some part of the full thickness of the plate extends around the bolts.

You could weld 4 square-ish tabs with holes in them onto the end plate. Get longer bolts and see if it is strong enough. I suspect that the welding operation will warp the plate though.

Add tubing around the bolts and between the plates to prevent the deflection. That or replace the plates with ones that have uniform thickness .

You could derate the hydraulic cylinder to a force that'll not yield the end plate.

On the next design you might consider replacing the milled flats for the bolt heads with counterbored holes,