PredicationsOf The Sectional EffectsThe supposing of the weightdistrubition as w(x) and the bouyancy distrubition as b(x).For the structuralequilibrium, these two components of ship’s moments, have to be balance on afixed or stabilized point.That means:The first equationshows that, the weight and buoyancy is equal to each other.The second formulademostrates that, the weight’s and buoyancy’s moments taken by the Xo point.Ifthese sitations are not providing, the structure is not in equilibrium andwhile to become in equilibrium state, the trim and the position of the draft isgoing to be in change.
In there, the supposing of the w(x) and b(x) is in fixedposition for making the analysis.But that hypothesis can not give guarantee forthe local stability between the weight and buoyancy.This situation, generatesthe balanced load dispersion on the all of ship lenght and this effectuates theshear forces and bending moments on the structural plate.When the examinationof the situation that arises in the terms of strength, the model of the ship asbeam that under the effects of the weight and buoyancy. ?ekil23: Thequasi-static forces actiong on ship structre and their affects.
?ekil 24:Thefirst step of the solving this problem is making the calculations for findingthe unbalanced force q(x) that along of the ship lenght.This is the differencebetween buoyancy and weight.Theinvestigation of the Q(x) shear force and M(x) bending moments on any part ofbeam that constituted by the not counterpoised force could done with theagreement of the balance between reactions on the beam and the loads on thebeam.Thisacceptance, specifies that the integral of the unstable force affects on thebeam and the shear force at any point of the structure is going to beequal.Secondly,the moments of the forces acting on a fixed point on beam mustbe in equality.
The bending moment will taken from the partial integration ofthe integral. Thementioned beam’s calculations for gathering the datas about the shear force andthe bending moment equilibrium must be done for each 3 situational process.Accordingto the datas, the characteristics of thestructure shows the differences for each analysis.After the determination ofthe beam effects consequences the longitudinal strength of the ship will becomputing.The measurements of the longitudinal strength provides the shearstress calculations and comparisons for the limiting criterias.