The ductility of structural elements and reinforced concrete structures is characterized by their ability to deform beyond the leakage limit, without significantly reducing their strength.
According to § 5.2.1 of EC8 there is a design option of the available ductility of the building.
Reinforced concrete buildings can be studied with two different design methods.
a) To be designed with the necessary ductility which means to have the required - necessary ability to consume seismic energy, but without losing their resistance to earthquake loads.
b) To be designed with low ductility, with low energy consumption, but with very high dynamic strength.
They are two different design methods that can not work together, because ductility allows inelastic deformation, while dynamic strength requires rigid walls of diaphragm function.
A pillar that deforms elastically or inelastically, cannot work together with a rigid elongated wall to resist seismic loads, because the elongated rigid wall resists from the beginning of the deformation, while the pillar recedes, due to its elasticity. or the ductility inelasticity, which follows.
As I mentioned before, according to § 5.2.1 of Eurocode 8, (EC8) there are three design options with different available ductility with a corresponding increase in dynamic strength when the ductility decreases, or in other words, an increase in ductility as the dynamic strength of the construction decreases .
I will strongly disagree with the Eurocodes 8. They can not work together flexibility, ductility and dynamics as they plan today.
Only the design that I suggest to you in the photos achieves a combination of flexibility, ductility and dynamics together. https://www.youtube.com/watch?v=IO6MxxH0lMU
In the dynamics of structures we study the structures in dynamic strain as a consequence of seismic movement of the ground. What my method is studying is how it will help the response dynamics of structures in terms of dynamic equilibrium equation, , using external dynamic response factors, with and without damping.
A short pillar and a normal pillar do not resist the earthquake together, because the short pillar receives all the stresses on its own because it is rigid, while the normal pillar gives way to elasticity.
The result is that the short column fails first because it is unable to pick up all the earthquake loads on its own. The same goes for a wall and a pillar. The wall as more rigid than the pillar receives all the tension on its own, and will be the first to fail.
How Eurocode 8 does not allow short columns but allows design with columns and walls together is worth mentioning.
My opinion is that either you have to design dynamically, or with available ductility
Both dynamically and ductility contribute to the reduced reaction of the structure to the earthquake.
Within the elastic displacement phase all the energy of the earthquake is stored in the trunks of the beams and columns and returns in the opposite direction, like the spring. We have no failures in elasticity. When the displacement grows larger than the elastic limit we have inelastic displacement with leaks - cracks. To manage the inability of seismic designs to control the inevitable inelastic displacement, they built the Ductility mechanism. They are unable to control the deformation. This is the problem, and Ductility just manages it better. But it does not solve the problem of deformation which causes from failures to collapse of structures.
Seismic damping consists of different damping mechanisms. 1) The horizontal seismic damping (bearings) limit the acceleration of the ground to pass on the construction. 2) Ductility is also this mechanism of seismic damping, because with the small failures on the trunks of the beams that it allows to be made, it releases seismic energy. 3) Hydraulic systems create seismic damping by converting the kinetic energy of the earthquake into thermal energy through its liquids which are heated when compressed by the displacement of the piston. 4) Elasticity is the vestibule of inelasticity and it also consumes seismic energy because heat is produced in the steel molecules when it receives stresses. There are other seismic damping systems that each operate differently in different areas of the structure to provide basically less instantaneous high seismic intensities on the structure. When we talk about dynamics this is something else. It is not seismic damping. It is a force against another force The design method I suggest involves something completely new and that is that it receives power from an external factor (that of the soil) and transfers it to the structure to help the structure respond dynamically against seismic forces, in order to have a balance of forces and not failure. This external force factor can be used to increase the dynamics of structures. It is not a seismic damping mechanism. So some who try to compare bearings with the external factor dynamics offered by my patent are misplaced because they compare two different things that have nothing to do with each other. However, if we want to use the invention as a seismic damping mechanism before it acts dynamically, then we simply place a seismic damping mechanism on the patent mechanism which will resiliently resist seismic shifts by drawing the reaction force from the ground before the main mechanism of the patent action dynamically to stop the inelastic displacement of the construction. In the dynamics of structures we study the structures in dynamic stress as a consequence of seismic movement of the ground. What my method is studying is how it will help the dynamic response of structures in the dynamic equilibrium equation, using external dynamic response factors, with and without damping.
As long as the displacement holds each part of any structural element within an elastic region, all the energy stored in the structure will circulate at the end of the cycle, in the opposite direction. This displacement region is called the elastic region, in which no failures are observed. If the seismic energy (measured by ground acceleration) is too large, it will produce excessively large displacements that will cause a very high curvature in the vertical and horizontal elements. If the curvature is too high, this means that the rotation of the sections of columns and beams will be well above the elastic area (Compressive deformation of concrete over 0.35% and reinforcement fiber tendencies above 0.2 %) beyond the leakage limit. When the rotation exceeds this limit of elasticity, the structure begins to "dissolve the energy storage" through plastic displacement, which means that the parts will have a residual displacement that will not be able to be recovered (while in the elastic region all displacements are recovered).
Ductility and elasticity,the two most important terms that are discussed frequently in structural engineering. Elasticity defines about how much the material is elastic, that is to which extent the deformations are proportional to the forces applied on the material.
Elasticity defines about how much the material is elastic, that is to which extent the deformations are proportional to the forces applied on the material. While ductility defines the capability of the material to get itself stretched beyond the elastic zone.
Within the elastic displacement phase all the energy of the earthquake is stored in the trunks of the beams and columns and returns in the opposite direction, like the spring. We have no failures in elasticity. When the displacement grows larger than the elastic limit we have inelastic displacement with leaks - cracks. To manage the inability of seismic designs to control the inevitable inelastic displacement, they built the Ductility mechanism. They are unable to control the deformation. This is the problem, and Ductility just manages it better. But it does not solve the problem of deformation which causes from failures to collapse of structures.
Seismic damping consists of different damping mechanisms. 1) The horizontal seismic damping (bearings) limit the acceleration of the ground to pass on the construction. 2) Ductility is also this mechanism of seismic damping, because with the small failures on the trunks of the beams that it allows to be made, it releases seismic energy. 3) Hydraulic systems create seismic damping by converting the kinetic energy of the earthquake into thermal energy through its liquids which are heated when compressed by the displacement of the piston. 4) Elasticity is the vestibule of inelasticity and it also consumes seismic energy because heat is produced in the steel molecules when it receives stresses. There are other seismic damping systems that each operate differently in different areas of the structure to provide basically less instantaneous high seismic intensities on the structure. When we talk about dynamics this is something else. It is not seismic damping. It is a force against another force The design method I suggest involves something completely new and that is that it receives power from an external factor (that of the soil) and transfers it to the structure to help the structure respond dynamically against seismic forces, in order to have a balance of forces and not failure. This external force factor can be used to increase the dynamics of structures. It is not a seismic damping mechanism. So some who try to compare bearings with the external factor dynamics offered by my patent are misplaced because they compare two different things that have nothing to do with each other. However, if we want to use the invention as a seismic damping mechanism before it acts dynamically, then we simply place a seismic damping mechanism on the patent mechanism which will resiliently resist seismic shifts by drawing the reaction force from the ground before the main mechanism of the patent action dynamically to stop the inelastic displacement of the construction. In the dynamics of structures we study the structures in dynamic stress as a consequence of seismic movement of the ground. What my method is studying is how it will help the dynamic response of structures in the dynamic equilibrium equation, using external dynamic response factors, with and without damping.
In seismic design there are projects of importance for which the study follows the complete seismic design and projects that use partial seismic design. This is done to reduce the cost of construction. Even in Greece there are three seismic hazard zones which also determine the choice of seismic design. The complete seismic design uses large walls which increase the mass of the construction and therefore the seismic loads in the cross sections. But because the cross sections are large the loads are smaller. Large walls with low height are of diaphragm function, ie they are not affected by axial and bending seismic loads. But they lower the torque at the base, and strain the joints with torque. This means that the weak beams will fail. If we impose pre-stress on the cross sections of the walls, they will increase their shear strength, the floor shear and the base shear. The torques, however, will not stop bothering the cross sections of the beams. If we build stronger beams we will greatly increase the mass and therefore the seismic loads. Is the solution for seismic design pre-tensioning of the walls from all their sides with simultaneous anchoring of the tendons to the ground? Question. 1) Would the wall lower high torques at the base, with the specific prestressing + anchoring to the ground? the answer is no 2) Would the high torques at the nodes be eliminated? The answer is yes 3) And where would the seismic forces be directed? The answer is they would be diverted into the ground. 4) Would there be deformation in the body? The answer is no. Only torsional displacements in asymmetrical structures and high-rise structures, and treated with the correct dimensioning of the walls.
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