Chetankumar Mohane

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    1. Please suggest me books that contains problems on manufacturing processes like forming, forging, drawing, casting, punching etc. I have P N Rao’s book which elaborates very good theory but it does not have enough no of solved problems 🙁 Please suggest me any book name or if anybody has a soft-copy then give me link….

    1. @I n I : Its my Pleasure…

    1. @Dinesh: Ok I wants to say that I am not too good in this Forming section but still I will try to solve this; Lets see how much can I help you !!!
      Say, Original c/s Area = O.A.
      Final c/s Area = F.A.
      Area After First Die = A1
      Original Length = O.L.
      Final Length = F.L.
      Now O.A. = (pi/4)*(10^2) = 78.5398 mm2
      A1 = (1-0.35)*(O.A.) = 0.65*(O.A.) = 51.0508 mm2
      Similarly for the area after 7th die
      = 0.65*0.65*0.65*0.65*0.65*0.65*0.65*(O.A.) … .. (For 7 dies)
      = (0.65)^7 * (O.A.)
      = 3.8502 mm2 = F.A.
      Now, as True strain is instantaneous % of change in length of specimen & it is given by,
      True strain (TS) = Natural log of (O.A./F.A.)
      = ln (78.5398/3.8502)
      = 3.0155 ———————————–ANS
      Final length can be calculated by using constant volume principle as,
      Initial Volume = Final Volume
      (O.A.)*(O.L.) = (F.A.)*(F.L.)
      78.5398 * 100 = 3.8502 * F.L.
      F.L. = 2039.8888
      = 2040 mm ————————————-ANS
      Now, For force we have to calculate a Draw Stress after first die,
      using uniform energy deformation method,
      Draw Stress (D.S.) = Y * ln(O.A./A1) …… … (Y = Yield Strength)
      (Note this formula can be used for only Ideal Conditions i.e. neglecting friction and redundant work)
      Hence, D.S. = 200 * ln (78.5398/51.0508)
      = 86.1568 N/mm2
      Now, Drawing Force through first die is,
      Drawing Force (F) = (D.S.)*(A1)
      = 86.1568 * 51.0508
      = 4398.3735 N
      = 4.4 kN ———————————ANS

      Note: Please check the answers & do notify in reply. If possible then mention the answers (options) along with the questions.

    1. Check out the NPTEL video lectures on Thermal Engineering by PK Das. The video lectures are really very good giving out basic knowledge of Thermal Engg.
      Here are the links:
      Lecture 1 : Introduction & Definition

      Lecture 2 : First Law of Thermodynamics (Open System)

      Lecture 3 : First Law of Thermodynamics (Closed System)

      Lecture 4 : Second Law of Thermodynamics

      Lecture 5 : Second Law & carnot Principle

      Lecture 6 : Properties of Pure Substances

      (Guys do use InI community regularly)

    1. first of all sorry for such long delay 🙁
      Anyway I think the data given is incomplete in this question that’s why now I am giving u only formulas:
      a) For Latent heat calculate “B” from the formula as:
      t = B * [(Casting modulus)^n]
      t = Solidification Time (given)
      B = Mold Constant
      n = 1.5 to 2 (Take 2 if not given)
      Then after finding “B” calculate Latent heat as:

      B = {[(ρm*L)/(Tm-T0)]^2}*{[3.1428/(4*K*ρ*C)]}*{1+[(Cm*ΔTs)/L]}

      Tm = melting or freezing temperature of the liquid
      To = initial temperature of the mold
      ΔTs = Tpour − Tm = superheat
      L = latent heat of fusion
      K = thermal conductivity of the mold
      ρ = density of the mold
      C = specific heat of the mold
      ρm = density of the metal
      Cm = specific heat of the metal

      b) For Fluidity of Short Freezing Range Alloys the formula is,
      Fluidity Distance, Lf = V * t

      V = flow velocity
      t = solidification time

      If the data is not given in the problem then take any appropriate material & take respective data & put it in formula… 🙂

      Well I don’t think this kind of question can be asked in GATE; if asked then it should be deserve 10 marks lol …
      Hope this could satisfied you a bit…. … .. .

    1. yes u can focus on your strong subjects but beware u should be 100% prepared on what u wants to study by the time of exam !!! U have a time now but don’t waste ur time much on deciding the subjects !!!!
      It is good enough to prepare 60 to 80% of the whole syllabus…

    1. if u don’t have some books as mentioned in “inspirenignite – link” then u can try these ones (some of the books are same)
      1. Engg. Thermodynamics – P.K. Nag
      2. I.C. Engine – M.L. Mathur, RP Sharma
      3. Gas Turbine and Propulsive Systems – P.R. Khajuria & S.P. Dubey
      4. Fluid Mechanics – Modi & Seth, R.K Bansal
      5. Compressible Flow – S.M. Yahya
      6. Heat and Mass Transfer – JP Hollman, R.C. Sachdeva
      7. Refrigeration and Air Conditioning – CP Arora, Domkundwar
      8. Fluid Machinery – Jagdish Lal , RK Bansal
      9. Theory of Machines – RS Khurmi, Malik & Ghosh
      10. Mechanical Vibration – Grover
      11. Machine Design – Shigley, VB Bhandari
      12. Material Science – WD Callister, IP Singh
      13. Production Engg. – Kalpkjian Schmid, Amitabh Ghosh & AK Malik
      14. Industrial Engg. – O P Khanna, Buffa & Sarin
      15. Operations Research – Kanti Swarup
      16. Strength of Materials – Timoshenko, B.C. Punamia, Rama Murtha

Viewing 7 posts - 31 through 37 (of 37 total)