3d-design

3D-DESIGN

Philosophy for guiding design The general philosophy in the design is an approach to guide the overall goal of the design and the tendencies of the designer, as these do not conflict. 1. Use-centered design, which focuses on the goals and tasks associated with the use of the artifact, rather than focusing on the end user. 2. KISS principle, (Keep it Simple Stupid, etc.), which strives to eliminate unnecessary complications.

Philosophy for method of design Adopted design method is a broad area that focuses on: 1. Exploring possibilities and constraints by focusing critical thinking skills to research and define problem spaces for existing products or services - or the creation of new categories. 2. Better guidelines obtained by redefining the specifications of design solutions for traditional design activities (graphic, industrial, architectural, etc.).1.

Formulated design theory The magnitude of the unit elongation of the element given by the equation

εx = σx / Ε

(a)

Materials used in engineering structures have moduli that are very large in comparison with allowable stresses, and the unit elongation (a) is a very small quantity.

Extension of the element in the x-direction accompanied by lateral contractions,

εy = - υ σx / Ε, εz = - υ σx / Ε

(b)

Equations (a) and (b) used also for simple compression. Within the elastic limit the modulus of elasticity and Poisson’s ratio in compression are the same as in tension.

If the above element submitted to the action of normal stresses, σx, σy, σz, uniformly distributed over the sides, the resultant components of strain obtained by using Eqs. (a) and (b). Experiments show that to get these components, we have to superpose the strain components produced by each of the three stresses. By this method of superposition, we obtain the equations2

εx = [σx - υ (σy + σz)] / E, εy = [σy - υ (σx + σz)] / E, εz = [σz - υ (σx + σy)] / E 1

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Considering conservatively

We obtained

εx = 0,

εy = 0,

σx = υ (σy + σz),

εz = 0

σy = υ (σx + σz),

σz = υ (σx + σy)

3D-Design Logical Parameters Lateral shear stress, :ls = υ (:ac + ;va)

(5.1.1; 6.4.2, IS 8003)

Torsion stress, :tor = υ (:bt + :bc)

(6.2.1; 6.2.3, IS 8003)

Conclusions Fundamental basics may vary. Like, 1. Plane sections before bending will not remain so afterwards. 2. Material will not remain isotropic though it may be homogeneous. 3. Conduction and convection will vary in the three dimensions. 4. Deflection will reduce and natural frequency will enhance, thus increasing sustainability. 5. Torsion warping stresses will not effect.4.

Notations

ε - Strain, σ - Stress, E - Young’s Modulus of Elasticity, υ - Poisson’s Ratio Reference: 1. http://en.wikipedia.org/wiki/Design. 2. Timoshenko, S.P., Goodier, J.N., ‘Theory of Elasticity’. 3. "IS 800 - 1998, Code of Practice for General Construction of Steel", Bureau of Indian Standards, New Delhi, 1999. 4. http://www.pdfcoke.com/doc/6996977/Torsional-Warping-Stresses.

About the author Mahaveer Janapala is a Structural Engineer and Interface Manager in an EPC Company. He is a postgraduate in Structural Engineering and a graduate in Civil Engineering from Osmania University (www.osmania.ac.in). He has a post graduation in Biblical Counseling from ‘CARE’ Counseling Institute (http://carecounseling.mahalife.com/) affiliated to ‘TOPIC’ (www.topic.us). He was born (1977), brought up and educated in HyderabadIndia, presently working and residing in Mumbai, India.

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