Don Johnstone wrote:
I think you might find that most of the modern gliders we fly are capable
of withstanding more "G" than the human body can take.
Overstressing a modern glider is unlikely to result in a catastrophic
failure unless there is already damage.

If you want to go up and verify this in real, then please be so kind and
do so without an innocent passenger on board!

Modern gliders tend to be certified to JAR-22. Non-acro gliders are
certified in the utility category which means a max. load factor of
+5.3G at maneuvre speed and +4G at Vne. Safety factor ist 1.5 (for a new
glider, probably less for a worn-out one!). Since gliders tend to be
constructed to the minimum requirements, because more strength means
more material, hence more cost and less payload, both not desirable,
chances are you will break a glider when pulling 8G at Vne. 8G are
perfectly standable (albeit for most peoole not enjoyable).

BTW, for aero-reated gliders, JAR-22 requires a load factor of 7G at
Vne. Earlier certified gliders are rated for less, only few gliders
(Swift, Fox) are rated for a higher load factor.