|
|
The Offered Directions in Development and Perfection of Protective Structures and Buildings |
|
|
|
|
|
|
|
|
|
The Welded All-Metal
“Sandwich
Plates” as Elements of Protection Structures
By Valeriy S.
Kogan, Ph .D. (Eng.)
Below are offered for elaboration
and introduction the welded all-metal “sandwich plates” as enclosure elements of
protection structures subjected to action of concentrated and distributed shock loads. The patentable idea of
such structural elements proposed by Valeriy S. Kogan has no analogs in world practice.
1. The “sandwich plates” consist of two “facings”
– flat metal sheets (outer and inner), and of joining them shear- stiff “core” –
a regular cellular structure of various configuration made of special roll-formed thin-walled metal profiles produced
in a waste-free technology.
There is possible, to damp
out a share of dynamic loads by means of including discrete absorbing parts into the “core” system.
2.
The elements of plates (sheets and profiles) are manufactured from special high-strength and heat-proof steels or titanium
alloys. The “facings“ and the “core” are joined together by the electric
or laser spot welding, in necessary cases – in combination with heat-resistant glues.
3.
The “sandwich panels” offered may be conditionally divided into following three groups depending
on expected (design) shock loads and on spaces between main load-bearing elements of the protection structure. The plates
of these three groups differ by the “core” structure, manufacturing technology and economic
effectiveness.
4. Group 1 –
the plates of 1 15/16" - 3 7/8" (50…100 mm) overall thickness, acting under load
as flexible plates or plates of finite stiffness. Their load bearing capacity is
limited by their spaces and by using in the “core” structure only limited (small height) range of
roll-formed profiles.
5. Group 2 –
the plates of 3 7/8" - 9 11/16" (100…250 mm) overall thickness, acting under load as plates of finite
stiffness, or as stiff plates. Their load bearing capacity may be sufficiently increased in comparison
with the group 1, when using an extended range of roll-formed profiles for the “core”
structure ensuring the increased security of their connections.
6.
Group 3 – the plates of 9 11/16" - 19 5/8" (250…500 mm)
and more overall thickness, acting under load as stiff plates. Under condition of using the special
roll-formed profiles for the “core” structure, the stiffness and load capacity of this
plates may be increased practically without limitations.
It’s especially necessary
to note, that groups 2 and 3 cover also a special kind of designs under the conditional name "trampoline". These
plates, due to elasticity of a "core" as though "spring" under shock loads, extinguishing thus a significant part of
dynamic loadings and raising thus reliability of offered protection.
--------------------------------------------------------------------
Copyright © Valeriy
S. Kogan, Ph .D. (Eng.), 05/20/2007, Chicago, USA
e-mail : vskogan@yahoo.com |
|
|
The Offered Directions in Development and Perfection of Protective
Structures and Buildings
All the structural solutions described below [based on the verified ideas
and patents elaborated by or in partnership of Valeriy S. Kogan, Ph.D. (Eng)]
may be conditionally classified as sandwich structures consisting of two load-bearing outer layers (“facings”)
and of disposed between them middle layer (“core”)ensuring the joint working of the “facings” under
the load, including dynamic (shock) ones, and other actions from outside.
Three principal types of structural design are offered:
1-
the sandwich plates and cylindrical shells with sheet facings;
2-
the “plate-latticework” systems;
3-
the precast and precast-cast in place systems of modular hollow blocks with
filling.
Type 1
The “facings” of the sandwich plates and cylindrical shells
may be made of :
·
flat or corrugated sheets of steel or titanium alloys
( Fig.1.1 );
·
high-strength, heat-resistant
reinforced concrete;
·
“armocement”
(fine-grain concrete reinforced by steel wire mesh);
·
high-strength special concretes dispersely reinforced
by steel or mineral fibres ( Fig.1.2, 1.3 ).
The “core” may be made of:
·
special (including
polymer-based) concretes;
·
high-strength dispersely
reinforced concretes;
·
aluminium alloys
dispersely reinforced by high-strength mineral fibres.
Some methods of connecting the facings with the core in abovementioned
structures are invented and patented by V.Kogan.
Type 2
The “plate-latticework” systems
include:
· the “tension chord” (from inside) consisting of longitudinal and diagonal metal profiles:
· the “compression chord” (from outside) consisting of interconnected rigid plates (panels), or having the
same structure as the “tension chord, when outer facing consists of flexible
(membrane) metal sheets;
· the space latticework of metal profiles connecting the “chords” and ensuring their joint working under
outer loads, including shock one.
This system ensures the survivalability of
the enclosure structure even under considerable damages (breaches) of the outer plates (sheets), due to redistribution of
internal forces among nondamaged elements of the system.
The profiles of “chords” and
space latticework may be made of high-strength heat-resistant steels, or of titanium alloys.
The rigid plates (panels) of the outer “chord”
may be:
·
precast plates of reinforced concrete, of “armocement”
(see above), or of dispersely reinforced concrete ( Fig.2.1 );
· sandwich panels with the sheet facings of steel or titanium alloys and the core of dispersely reinforced aluminium
alloys, or lightweight concrete (
Fig.2.2 ).
The flexible (membrane) sheets of the outer facing may be made of steel (including heat-resistant), or of titanium alloys. The
membranes cellwise fixed to longitudinal and lateral metal profiles of the outer
“chord” are prestressed by means of adjustable ties or struts in the centres of cells.
Type 3
The structures of this
type are especially intended for fast-erected field fortifications (wall fencings, breastworks, pits and manholes, blockhouses,
etc.) ensuring the protection mainly from any horizontal shock loads. The basic elements of such structures are prefabricated
modular box-like hollow
blocks made
of high-strength,
fire resistant
dispercely reinforced
Materials ( Fig.3.1
). After their erection, the blocks are tierwise filled by the
ballast material. This system, patented by V.Kogan, was repeatedly approved in building practice of several countries ( Fig.3.2 ).
The modular blocks may be made of:
· high-strength and heat-resistant cement-based concretes dispercely reinforcered by mineral
fibres
( Fig.3.1 );
· heat-resistant polymer-based concretes dispercely reinforcered by mineral fibres ;
· high-strength aluminium alloys dispercely reinforcered by super-thin mineral fibres.
The ballast filling
of the block structure may be of:
·
sand, gravel, or fine broken stone ( Fig.3.2 );
·
concretes on high-strength binders, reinforced
by steel bars;
·
the same, dispercely reinforced by steel and
mineral fibres.
|
