Building construction with sandwich panels has become very common in constructions. And sandwich panel development is also being advanced by a wide variety of organizations. It is only becoming difficult to adhere to the current customary use.
If you compare the architectural material files from a few decades ago to the current literature, you'll see the rapid increase in the number of sandwich components of any kind. However, even the definition of “sandwich structure“ applied to sandwich panels is still not easy. The official bodies of the construction sector provide a consensus on the following definition;
Sandwich Building
"It is a structure containing a combination of alternative, different, simple, or composite materials that are assembled together and firmly fixed together with the goal of harnessing the structural advantages of each.
This is the best definition possible of all other definitions. In any case this term implies that the parts that form a sandwich panel, as used in buildings, are connected together in some way to provide unified action for the environment in which they are exposed.
Sandwich panels can differ from a curtain wall, which can confine units. A sandwich panel can be a curtain wall, but it can't just be called a curtain wall. A sandwich panel may or may not be if it is a curtain wall. Although the idea of structural sandwich construction is not entirely new, only in recent decades has sandwich panels found fairly widespread use in buildings. Among the first significant sandwich panels were various combinations of cement-asbestos sheet coatings and fiber sheet cores.
Generally, these were used in combination with a type of frame. Thus sandwich panels support loads applied directly to them, but do not support the full load of the building. This type is a typical early house construction.
Most industrial and commercial use of sandwich panels also included a frame in which sandwiches were placed.
The main reason for using sandwich panels is the structural efficiency that can be achieved. Thin, hard, strong, rigid coatings are tightly attached to thick, lightweight cores. The geometry of this combination, coating material and core material can easily provide great strength and stiffness with little weight or thickness. Thin, strong surfaces provide resistance to internal bends, margin, while core material is resistant to cutting. It also stabilizes the surfaces against buckling.
As noted above, the current use of sandwich panels is only semi-structural; that is, the panels are incorporated into a structural frame that carries most of the load, and the sandwich panels only carry directly loaded loads.
Typically, these sandwiches are wall panels exposed to only transverse loads. They transmit these loads to the primary structural framework. In fact, this issue, which construction sandwich panels are expected to make, is a habit. For many applications, construction is an understanding that limits the structural use of sandwich panels. There is also no natural reason for lightweight structures, especially houses and one or two-story commercial or industrial buildings, that construction sandwich panels should not carry all the loads and eliminate the structural frame.
Many sandwich panels can or do full structural impact with relatively minor modifications.
Properties Of Sandwich Panels
Thermal Properties
One of the most attractive features of construction sandwich panels is their ability to provide high thermal insulation efficiency (i.e., a low overall transfer coefficient) with minimal heat. There are many thermally efficient core materials that are structurally appropriate. The thickness of sandwich panels is determined by structural demands ( such as the minimum dimensions of door and window frames) and other considerations, not thermal. The second thermal properties of sandwich panels are not very good for each sandwich panel. Materials consisting of sandwich panels may have different thermal expansion coefficients. And the temperature change leads to different dimensional changes in various parts of the sandwich. This, bending or sprains can easily lead to deterioration. Also, one side of a sandwich, such as the outer face of a wall panel, can undergo significantly larger temperature changes than the other. Even if the various parts have equal coefficients, they can produce thermal gradients leading to differential expansion or shrinkage. The result is disruption again. Careful design is required if these effects are to be minimized.
Moisture and its effects closely related to thermal properties
Changes in temperature can cause changes in air pressure within the sandwich by a pumping action that leads to water vapor leaking into the panel. Condensation may occur on the panels and measures must be taken to get rid of the water or prevent it from accumulating in the first place. It requires the creation of airtight sealed panels, or open structures that allow moisture to enter and drain free.
Acoustic Problems
The basis of acoustic problems is the tendency of sound to tend towards light frames and boards, open plans, and often space dividers. Walls made up of sandwich panels, compartments, space separators and other semi-structural parts of the building contribute to this situation.
The heavier permanent structure previously used provided good acoustic barriers due to its mass. Today's lightweight structures tend to convey sound easily. The problem is to keep the acoustic properties of lightweight panels close to the advantages of continuous rigid construction, and to provide good acoustic barriers and sound insulation. For this reason, the basics of sound transmission should be re-examined in sandwich panel making. Instruments that provide high acoustic impedance should be used without resorting to heavy mass. For this reason, support systems are important in the design of sandwich panels, including acoustic reasons. It's not just good sandwich panels.
System Requirements
The Panel must be part of a building. It is also essential that some systems are used to incorporate sandwich panel into the building. In fact, the insertion system can become a very important element, and a poor connection can easily make a good sandwich panel a problem.
While the sandwich system itself is modular, it must adapt itself to non-modular designs. It should allow sandwiches to be combined with other ingredients. Unless such flexibility is provided along with simplicity, the entire sandwich panel and attachment system will cause serious limitations in practice.
In Terms Of Architectural Design
Construction sandwich panels pose both an opportunity and a challenge for architects. The many materials that can be used within them provide a wide range of patterns and colors, and the available sizes and shapes provide considerable flexibility for design. On the other hand, a large number of these types need to be used to reduce manufacturing costs. Shipping requirements create constraints on sizes, shapes, and weights.
The panels must also adapt to other features, such as windows and doors, which are fabricated at the factory and must be used repeatedly. It can be a big problem in aesthetics. It can create monotony and be sharply criticized. The design problem can also be a serious problem, but an aesthetically satisfying and also efficient building can emerge if planned successfully. The fact that the panels produced in the factory can be converted into different shapes when desired creates a great advantage.
Regulations
Sandwich panels are largely New compared to other architectural components. In many cases building construction procedures and other regulatory rules have not captured the inherent possibilities of sandwich panel use. It is also likely that these regulations were written to make the adoption of a sandwich panel system difficult. This is especially true for commonly found specification Type Codes. Officials who write the procedures are reluctant to leave the familiar old practice, even if they allow it to be done.
A great educational effort will be required. Architects, engineers, builders and owners do not have to be convinced of the soundness of the system, but they have to convince the authorities. You should be able to easily convince that the sandwich panels used really meet the conditions.
Core and Coating Materials
Many different materials were used in the construction sandwich panels. It is actively being developed or researched in many other composite materials. Sheet between coating materials, cement, aluminum, plywood, stainless steel, chipboard, porcelain enameled steel and aluminum, reinforced plastics, high pressure laminates, and transparent plastics are reinforced concrete.
Core materials are also equally diverse. Glass includes styrene, urethane, phenolics and other plastic foams; materials such as sunflowers, plywood, balsa wood, wood and metal grating; honeycombs, bulkheads, glase fiber mats, and expanded concrete form core materials.
An important material in many sandwiches is the adhesive used to bind various ingredients together. Structurally, the adhesive must be able to withstand many repetitions of slip and pull stresses, as the sandwich is subjected to loads of various types. It needs to be completely waterproof, able to withstand high and low temperatures, and resistant to attack by mold and animal organisms.
Most adhesives used in construction sandwiches are based on synthetic resins, thermosets, or thermoplastics, which are usually combined with other materials such as rubber. However, not all are synthetic, and various adhesives are based on naturally occurring materials, including asphalt. Strength, durability, and sufficient flexibility to take differential forces are the basic design requirements of a good adhesive.
Sealants and seals
Sealants and seals have become important components of buildings. There is a lot of activity in this area. These materials are handled separately by building research organizations. Sealants and seals are arguably the first of importance in any system that uses sandwich construction.
Outdoors, in addition to providing airtight joints, they should also leave dust out, help stop airborne noise, and provide pillows to prevent squeaking and other noises as the panels expand, shrink and move under load.
Air tightness is not important for interiors, but sealing materials and seals should be relied upon for sound transmission and noise formation.
Severe conditions may be applied on sealants and seals. The panels expand and contract with changes in temperature, humidity, or both. So a thin seal or joint can easily be subjected to stresses and pressure forces of 50 percent or more.
The joint is expected to remain tight at high and low temperatures. The material should stick to adjacent panels or press tightly, not harden enough to crack at low temperatures, and not dangle while hot. It should show extreme resistance to fatigue stresses and should not deteriorate for long periods when exposed to sunlight, moisture, freezing and thawing. Preferably it should be applied easily. It is not surprising that they are a very critical area for these reasons.
Quality Control
The importance of quality control in the production of sandwich panels cannot be emphasized. In many ways the most critical aspect of a sandwich panel is the bond line between the various parts. In particular it is the bond between the core and coatings. Multiple promising combinations have failed. Because he couldn't tie the pieces well enough. Stresses in the ligament can be severe due to loads and thermal changes. Moisture penetrating the interior can cause delamination, and even if it is not dangerous, an unpleasant situation can easily occur to the eye.
Obviously, the various parts of the sandwich panels should be enough for the job. Surfaces must be resistant to air and wear and maintain their appearance. Even if changes occur, the core material should not deteriorate over time and with changes in moisture content. The dimensional tolerances of sandwich panels should often be close together. With the repeated use of sandwiches in large numbers, changes in size are likely to be noticed. When highly reflective plane surfaces are found, as with a number of sandwiches, the waviness and overhangs are conspicuously noticeable. Therefore, rigorous quality control becomes mandatory.
External surface and other structural forms
It is the fillings in the frames that will probably carry the bulk of the load in the structure. It is a natural tendency to think of sandwich panels as a flat wall or roof cladding. In any case, the panel itself and the edge strips are considered a simple relation. Some of the best uses of sandwiches in the future may be apart from simple, flat panels.
Use in open spaces exposes sandwich panels used in different forms as a requirement in situations such as covering the top of large spaces. Folded and shaped plates adapt particularly well to these requirements. Despite the problems of bending and bending of flat panels in large areas, there is a need to convert the sandwich panel into various forms.
Status of sandwich panels used in Glass Reinforced Plastic compared to general characteristics
When we look at these properties of sandwich panels, the analysis of why Glass Reinforced Plastic, i.e. fiberglass panels, is used extensively. Fiberglass is a sandwich surface in itself.
The sandwich panels supported by this material meet the requirements of the sandwich panels in the best way because of the natural elements that come from the structure. In summary, they are light, flexible, and sandwich panels built with glass reinforced sheets and foam systems absorb acoustically very well. They can be combined very easily into the building's support systems expected from sandwich panels. They can be produced in different architectural designs for different projects. They do not create a monotonous design. They can be produced with a choice of thousands of different shapes and colors.
Since it is an increasingly used material, it has become the building components that the building supervisors believe are well known and that fall under the regulations.
Because the materials that make up the sandwich are naturally made up of glass reinforced plastic panels that are resistant to corrosion, moisture, wear in weather conditions, tensile and stress forces, they are more efficient in the structures than any other sandwich panel alternative. Core and coating materials are close to each other due to thermal stress coefficients materials do not separate from each other with temperature differences. Considering the expectation of the best sandwich panels, the sandwich panels created from glass reinforced plastic sheets are easily understood why we see more and more in the structures every day.