Eiffel Tower and Femur

8/13/2019 Eiffel Tower and Femur

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The femur or thigh bone, is the closest to the

center of the body. The pair of femur in humans

has been shown in Figure 1.

The head of the femur articulates with the

acetabulum in the pelvic bone forming the

hip joint, while the distal part of the femur

articulates with the tibia and patella forming

the knee joint. (Figure 2) .By most

measures the femur is the strongest, heaviest

and longest bone in the body.

The femur contains two distinct morphological types of bone:

Cortical (compact) bone Cancellous or Trabecular (spongy) bone

These are shown in the figure b. Cortical bone forms a dense cylinder down the

shaft of the bone surrounding the central marrow cavity. While cortical bone

accounts for 80% of the mass of bone in the human body, it has a much lower

Figure a

Figure b


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surface area than cancellous bone due to its lower porosity. Cancellous (or

trabecular) bone is located at the ends of long bones, accounts for roughly 20% of

the total mass of the skeleton, and has an open, honeycomb structure. It has a much

lower Youngs modulus than cortical bone, and this graded modulus gradually

matches the properties of the cortical bone to the cartilage that forms the

articulating surface on the femoral head.

Stresses

Bones such as the femur are subjected to a bending moment, and the stresses (bothtensile and compressive) generated by this bending moment account for the

structure and distribution of cancellous and cortical bone.

In the upper section of the femur, the cancellous bone is composed of two distinctsystems of trabeculae. One system follows curved paths from the inner side of the

shaft and radiates outwards to the opposite side of the bones, following the lines ofmaximum compressive stress. The second system forms curved paths from the

outer side of the shaft and intersects the first system at right angles. These

trabeculae follow the lines of maximum tensile stress, and in general are lighter in

structure than those of the compressive system.

The thickness of the trabeculae varies with the magnitude of the stresses at anypoint, and by following the paths of the principal compressive and tensile stresses

they carry these stresses economically. The greatest strength is therefore achievedwith the minimum of material.


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The distribution of the compact bone in the shaft is also due to the requirement to

resist the bending moment stresses. To resist these stresses, the material should beas far from the neutral axis as possible. A hollow cylinder is the most efficient

structure, again achieving the greatest strength with the minimum of material.

Diagram showing computed lines of constant stress from the analysis of various

transverse sections


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While designing the famous tower, Maurice Koechlin, assistant to Eiffel, the

architect of the tower, was inspired by the femur, the lightest and strongest bone of

the human body. The result has been a self-ventilated and strong structure. The

femur, which has been a source of inspiration for the tower, is in the shape of a

pipe and has a fusiform internal structure, i.e. in which the bone narrows in the

middle and expands at each end. This structure provides flexibility and lightness

for the bones, yet does not cause them to lose a bit of their strength. In buildings

that are constructed in this way, construction material is saved, and the

construction's skeletons gain firmness and flexibility.

In the 1850s, Meyer had studied the human femur, or thighbone, which connects to

the hip. This bone, the largest in our body, has an unusual off-center ball joint that

fits into the hip socket. For strength, the bones curved head has many internal

bone fibers, called trabeculae. These bone fibers crisscross each other in layers and

are precisely aligned to withstand the varying forces of tension and compression.

As a result of this ingenious design, the femur efficiently supports and transfers the

off-center weight of the person. The femurs ball joint may look awkward, but it

functions superbly for a lifetime of movement unless bone disease interferes.

Swiss engineer Karl Cullman later generated mathematical models of thefemur design.2In the late 1860s he noted that the trabeculae fibers closely

resembled the struts and braces used in buildings. Architect Eiffel then tookthese ideas and designed his famous Eiffel Tower, the tallest structure in the

world at that time, to be built with a minimum amount of iron for maximumstrength. The outward flares at the base of the tower resemble the upper

curved portion of the femur. The internal wrought-iron braces used in thetower closely follow the design of trabeculae within the femur.

The Eiffel Tower has been a Paris landmark for over a century. Including itsantennas, the tower reaches a height of 1,063 feet (324 m), or 81 stories. The
http://www.answersingenesis.org/articles/am/v4/n4/architects#fnList_1_2http://www.answersingenesis.org/articles/am/v4/n4/architects#fnList_1_2http://www.answersingenesis.org/articles/am/v4/n4/architects#fnList_1_2http://www.answersingenesis.org/articles/am/v4/n4/architects#fnList_1_2


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tower marked the entrance to the 1889 exhibition and was originally built as

a temporary structure. Competing architects scoffed at the tower, calling itan eyesore and predicting that it would collapse under its own weight.

However, it remains today, over a century later, a Paris landmark. It is the

destination of millions of tourists annually.

The Eiffel Tower today is considered a work of art. A true marvel of humanengineering, its elegant design was originally based on Gods design of the

human body. AsPsalm 139:14 declares, we are fearfully and wonderfully

made.

Compared to compact bone, cancellous bone has a higher surface area to

mass ratio because it is less dense. This gives it softer, weaker, and more

flexible characteristics.

The Eiffel Tower is anironlattice tower located on theChamp deMars inParis,named after the engineerGustave Eiffel,whose company

designed and built the tower. It has a height of 324 metres.

When it was completed in 1889, the Eiffel Tower was hailed as a marvel ofmans engineering. But its basic design was actually borrowed from the

work of an ancient designerthe Creator, who engineered the human femur.

In May 1884, Koechlin, working at home, made an outline drawing of theirscheme, described by him as "a greatpylon,consisting of fourlatticegirders standing apart at the base and coming together at the top,

joined together by metal trusses at regular intervals"

"not only the art of the modern engineer, but also the century of Industry andScience in which we are living, and for which the way was prepared by the

great scientific movement of the eighteenth century and by the Revolution of

1789, to which this monument will be built as an expression of France's

gratitude."
http://biblia.com/bible/nkjv/Psalm%20139.14https://en.wikipedia.org/wiki/Ironhttps://en.wikipedia.org/wiki/Lattice_towerhttps://en.wikipedia.org/wiki/Champ_de_Marshttps://en.wikipedia.org/wiki/Champ_de_Marshttps://en.wikipedia.org/wiki/Parishttps://en.wikipedia.org/wiki/Gustave_Eiffelhttps://en.wikipedia.org/wiki/Pylon_(architecture)https://en.wikipedia.org/wiki/Girderhttps://en.wikipedia.org/wiki/Girderhttps://en.wikipedia.org/wiki/Pylon_(architecture)https://en.wikipedia.org/wiki/Gustave_Eiffelhttps://en.wikipedia.org/wiki/Parishttps://en.wikipedia.org/wiki/Champ_de_Marshttps://en.wikipedia.org/wiki/Champ_de_Marshttps://en.wikipedia.org/wiki/Lattice_towerhttps://en.wikipedia.org/wiki/Ironhttp://biblia.com/bible/nkjv/Psalm%20139.14

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Eiffel Tower and Femur