halcyon
Well-Known Member
The A frame and heavy cable produce a bow in the crossbeam, only a slight one. This means the top face of the beam is in compression, the lower face in tension.
Now if you appl a load on the forestay to the centre of the beam, this tries to pull it up and straighten the beam. This puts the beam into a compression load, or at least tries to straighten. Which reduces the pre loaded compression stress in the top face, to a neutral one. Without the A frame, the beam would just bend up in the middle and give a tension load in the top face, not what you want.
What would give me concern, if only slightly.
The gap outer edge of A frame mounting plate, this is either the A frame legs bent, or the cross tube bent up, I think A frame legs bent as cable would be slack if the tube was bent. Has the A frame bending altered pre load on cross beam, depends how much pre-load the builder designed for, depends how critical.
The A frame mounting feet appear bent up, so only sitting on inner corner. This is producing a high stress point at this edge. There is stress here are movement can be felt between beam and mount. Added to this if the centre section through the nose is rigid, due chain locker and forepeak contruction, this his will add to stress raiser.
Both points are probably more medium term than short, but I would keep my on the movement of the crossbeam, and consult the builder on this problem.
Brian
Now if you appl a load on the forestay to the centre of the beam, this tries to pull it up and straighten the beam. This puts the beam into a compression load, or at least tries to straighten. Which reduces the pre loaded compression stress in the top face, to a neutral one. Without the A frame, the beam would just bend up in the middle and give a tension load in the top face, not what you want.
What would give me concern, if only slightly.
The gap outer edge of A frame mounting plate, this is either the A frame legs bent, or the cross tube bent up, I think A frame legs bent as cable would be slack if the tube was bent. Has the A frame bending altered pre load on cross beam, depends how much pre-load the builder designed for, depends how critical.
The A frame mounting feet appear bent up, so only sitting on inner corner. This is producing a high stress point at this edge. There is stress here are movement can be felt between beam and mount. Added to this if the centre section through the nose is rigid, due chain locker and forepeak contruction, this his will add to stress raiser.
Both points are probably more medium term than short, but I would keep my on the movement of the crossbeam, and consult the builder on this problem.
Brian
