I or H tiles and bricks for stronger, lighter assembled structures

[Peter Dow]

From the engineering consideration that regular tiles and bricks are far from optimal in terms of adding strength to structures, I've been considering that better would be the very particular shape of tiles and bricks illustrated in this image which is a version (representing steel) of a pattern I first posted here in a topic in The Lounge forum, Tessellated I - my simple technical drawing, coloured artfully

 

View larger version of Tessellated I in Steel 1800 x 800

 

Representing a surface of "I"-shaped (rotated by 90 degrees, "H"-shaped) steel tiles. The shape is of square proportions, the column of the I being one third of the width of the square and the top and the base one quarter of the height of the square.

 

I intend further design developments to the I or H tile and brick 2-dimensional pattern I have described here - specifically fleshing out the simple 2-D design into a more detailed 3-D design which introduces further efficient tile-to-tile / brick-to-brick interlocking or making-rigid features to enable the tiles or bricks to be able to be assembled together then disassembled when necessary without having to be cemented together like a brick wall

 

 

and without having to be glued onto a mounting surface like conventional tiles

 

 

The aim is to allow assembly and disassembly of tile or brick structures such as can be done with Lego and Meccano (kid's building toys) and using common methods employed in the design of many manufactured products which use such typical features as nuts and bolts and bolt-holes but many other variations to secure one part to another strongly but in a reversible and flexible way. The ability to disassemble is particularly useful for temporary structures, as is strength-to-weight ratio so that the parts of the structure can be moved easily to where they need to be erected.

 

 

So I still have some design thinking and technical drawing to do and then I'll need a fabrication plan suitable to my own means of production, limited to making small models.

 

For high strength-to-weight ratios for practical applications of this design, I suggest that materials useful will likely be metals such as steel and aluminium and for some applications plastics and in particular fiber-reinforced plastics offer very high strength-to-weight ratios and so may be even better.

[dimreepr]

I take it, from the op, the structures you intend are buildings, shelters, etc (please correct if I’ve missed the mark). The primary issue you will need to address is accuracy, the tiles will need to fit together precisely to avoid the need for mortar, as with traditional bricks. As for materials, what’s wrong with ceramics? Also look into the internal structure of your tile, to improve strength-to-weight ratios, such as honeycomb or simply hollow.

[John Cuthber]

Imagine grabbing the right and left edges of those tiled planes and pulling.

Without some sort of glue it will come apart with very little strength.

Edited January 7, 2013 by John Cuthber

[Enthalpy]

One essential condition for this shape is that the material doesn't break at the notches, that is it must be tough or resilient. A brittle material like brick or nearly any ceramic wouldn't fit, and this is a drawback, because ceramics make houses for being cheap.

 

Because of cost, your bricks will likely be hollow. Fine: plastics can be injected, metals cast. This eases as well the production tolerances, since hollow shapes can be designed to deform more easily. Looks even more like Lego.

 

Among plastics, polypropylene and some polyamides, as well as ABS and some kinds of PVC, are little sensitive to notches and rather affordable. Pity: all burn, some can evaporate or exsude toxic compounds, get brittle over time and especially at Sunlight... This choice needs a detailed analysis.

 

Short glass fibres can be incorporated to injected plastics. Still affordable, makes slightly stronger but not tougher, AND can improve the flame resistance.

 

Most metals can be cast, with zinc, aluminium, possibly magnesium being low-cost candidates. I believe injection (like plastics, well under the fusion temperature, compensate it with big pressure in a strong die) already exists for metal, allowing high production rhythm.

 

In a variant, you could cast concrete in a hollow shape made quickly by assembling your bricks, but this exists already with hollow ceramic bricks.

 

What about metal clamps that shrink when cooling down to ambient temperature? Shape memory alloys are too expensive, but bimetal springs look affordable.

 

In any case, remember how fast workmen go with cement! Challenging a well-established technology is always difficult.

[Peter Dow]

I take it, from the op, the structures you intend are buildings, shelters, etc (please correct if I’ve missed the mark).

Right on target, especially considering structures where more strength or less weight are advantageous enough to make a novel approach worthwhile.

The primary issue you will need to address is accuracy, the tiles will need to fit together precisely to avoid the need for mortar, as with traditional bricks.

An issue for mass production engineers if and when they decide to use this design but the requirement for precision is nothing beyond the state of the art.

As for materials, what’s wrong with ceramics?

Ceramics generally are not so good under tension and tend to fracture under shock loads, impacts and so on. Nevertheless there still could be a place for I-shaped ceramic bricks for some applications, such as where resistance to fire and heat is a particular requirement.

Also look into the internal structure of your tile, to improve strength-to-weight ratios, such as honeycomb or simply hollow.

Absolutely.

 

Thanks for your input dimreepr.

Imagine grabbing the right and left edges of those tiled planes and pulling.

Without some sort of glue it will come apart with very little strength.

Well spotted John and thanks for your diagram which makes your important point very well.

 

This is precisely why there is a need for a 3-dimensional design which introduces sufficient fittings, fasteners or fixtures or such as bolt-holes etc which ensure the columns of I's stay locked together. However, I am not thinking of glue or mortar because I want something which will disassemble quite easily. Glue actually isn't all that strong compared to say a nut and bolt.

Edited January 8, 2013 by Peter Dow

[dimreepr]

Imagine grabbing the right and left edges of those tiled planes and pulling.

Without some sort of glue it will come apart with very little strength.

 

Good point, though easily solved, turn the structure through 90 degrees and gravity would help to lock it especially with a roof on.

[Enthalpy]

I don't know if this shape-lock construction can become cheaper than brick and cement. But even if it doesn't, it may have applications, for instance as a shelter against hurricanes, or as seismic-proof construction.

 

One question if using metal or plastic: why have bricks or tiles rather than big panels?

[John Cuthber]

 

Good point, though easily solved, turn the structure through 90 degrees and gravity would help to lock it especially with a roof on.

That would help, dovetailing them would help even more, but it would make it more difficult to assemble.

[Peter Dow]

3-Dimensional model video

 

 

 

 

 

This video shows a model by Peter Dow (of Aberdeen, Scotland) of the 3-dimensional shape of a simple structure composed of 6 bricks or tiles, each of which, when viewed from one-direction anyway, is a 2-dimensional "I"-shape (equally when rotated by 90 degrees "H"-shaped).

 

This model has been made from aluminium tubing and in order to distinguish one brick from another they have been coloured using marker pens - so there are two bricks coloured blue, two coloured green and two coloured red. This colouring was necessary for clarity because otherwise the permanent joints within bricks (which are only an artifact of the method to make a brick from square tubing) might be confused with the simple touching surface where two neighbouring bricks abut, abutting securely but without being in any way stuck by glue etc.

 

The 2-D "I" shape being modelled is supposed to be of square proportions, the column of the I being one third of the width of the square and the top and the base one quarter of the height of the square.

 

These 2-D I or H shapes can be mathematically said to be able to tessellate a plane, that is to say, one can fit many of these shapes together to cover a surface completely.

 

This 3-Dimensional model reveals a further design feature of the I or H brick and tile structures, which secures the bricks and tiles together in 2 further dimensions, some such feature being necessary because the 2-D I or H shape in of itself only secures the bricks together in 1 dimension.

 

This feature is revealed here to be nothing more complicated than dowels or fixing rods which run in the vertical direction of the Is (or the horizontal direction of the Hs) through shafts in the Is' bases and tops and which serve to lock the tops and bases of neighbouring Is together, preventing movement radially from the dowels.

 

These dowels may henceforth be referred to as "Mazurka Dowels" named after the username of a scientist in an internet science forum who first correctly anticipated this feature of my 3-D design and its function to hold the structure together in all 3-dimensions, in a reply post to my topic there describing in detail only the 2-D tessellation, suggesting somewhat vaguely that some such design element was required for a good 3-D design with a view to seeing who would suggest the solution I had thought of first.

 

As I explained in that topic I could hardly call those dowels the "Dow dowels" there being too many dows in that name and anyway, my name can be used to reference this particular shape of I or H tile and brick and structures composed of them, as per "Dow tile" "Dow brick" "Dow I-tile" "Dow H-brick" "Dow I-H-brick" "Dow I-H-brick structure" "Dow I-structure" etc.

Edited January 9, 2013 by Peter Dow

[Peter Dow]

One essential condition for this shape is that the material doesn't break at the notches, that is it must be tough or resilient. A brittle material like brick or nearly any ceramic wouldn't fit, and this is a drawback, because ceramics make houses for being cheap.

 

Because of cost, your bricks will likely be hollow. Fine: plastics can be injected, metals cast. This eases as well the production tolerances, since hollow shapes can be designed to deform more easily. Looks even more like Lego.

 

Among plastics, polypropylene and some polyamides, as well as ABS and some kinds of PVC, are little sensitive to notches and rather affordable. Pity: all burn, some can evaporate or exsude toxic compounds, get brittle over time and especially at Sunlight... This choice needs a detailed analysis.

 

Short glass fibres can be incorporated to injected plastics. Still affordable, makes slightly stronger but not tougher, AND can improve the flame resistance.

 

Most metals can be cast, with zinc, aluminium, possibly magnesium being low-cost candidates. I believe injection (like plastics, well under the fusion temperature, compensate it with big pressure in a strong die) already exists for metal, allowing high production rhythm.

 

In a variant, you could cast concrete in a hollow shape made quickly by assembling your bricks, but this exists already with hollow ceramic bricks.

 

What about metal clamps that shrink when cooling down to ambient temperature? Shape memory alloys are too expensive, but bimetal springs look affordable.

 

In any case, remember how fast workmen go with cement! Challenging a well-established technology is always difficult.

Thank you very much for your post Enthalpy and for the benefit of your knowledge and wisdom. I have only got time to address your questions right now but I hope to return to the many other relevant issues you raised here when time permits.

 

I am unsure what exactly the shape of your "metal clamps" would be or how they would fit into a three dimensional structure of I or H bricks or tiles? Certainly metal is a ideal engineering material in many applications.

I don't know if this shape-lock construction can become cheaper than brick and cement. But even if it doesn't, it may have applications, for instance as a shelter against hurricanes, or as seismic-proof construction.

 

One question if using metal or plastic: why have bricks or tiles rather than big panels?

Well a big "tile" with features to attach to other tiles could be described as a big "panel" of sorts, right? Edited January 8, 2013 by Peter Dow

[Peter Dow]

 

Transcript of the video

 

 

Hi everybody and welcome to my "H" / "I" Bricks or HI-BRICKS & DOWELS demonstration video.

 

This is Peter Dow from Aberdeen, Scotland.

 

There are two components to a HI-BRICKS & DOWELS construction -

• the BRICKS, which you can either describe as "H"-shaped or "I"-shaped, depending on which way you turn them around
• and the DOWELS

 

The shape of the "H" or "I" bricks is designed so that they fit together to form a layer or a wall of bricks and importantly, the bricks, just by their very shape, immobilise each other from moving, in one dimension only.

 

Let's have a look at that.

 

Let's consider this green brick here as the fixed point.

 

We can see that it immobilises its neighbouring bricks in one dimension. They can't move with respect to the green brick in this dimension. So that's locked. Even though there is no bricks here or here, the very shape stops it moving in that dimension.

 

Now the shape doesn't stop the bricks moving with respect to each other in that direction, or in that direction but they are fixed in that one dimension.

 

 

Now if we want to make a rigid structure of bricks in all three dimensions but without using mortar or glue so that we can assemble and disassemble the structure whenever we like, what we need next are the DOWELS.

 

As you can see, the "I" or "H" bricks have shafts running through the corners so that you can run a dowel through the corners - two shafts, four holes per "I" or "H" brick.

 

And when you assemble the bricks you can slide the dowel in ... and this forms a structure which is rigid in all three dimensions, which is what we need to form structures.

Edited January 14, 2013 by Peter Dow