CAE (Comprehensive Analytic Engineering ) , Inc.

CAE SETS (Structure Engineering Turnkey System): True #1

THEORY BREAK-THRU TRUE TENSION-ONLY FAKE TENSION-ONLY ZERO-COMPRESSION TENSION-ONLY
TRUE REPRESENTATION MISREPRESENTATION
USP, 1976 (UTP,1970) STAAD III ALL OTHERS
ELEMENT BEAM,TRUSS & ONE-Way ELEMENT BEAM, TRUSS (BEAM & TRUSS:NO/YES ?) ELEMENT BEAM & TRUSS YES/NO ?
PRECISE RESULT with Euler Critical Buckling Compression NO NO ?
Option for Zero Compression: YES (also as a tool to check lower tech competitors' programs) NO N/A
Correct Result for Deflection Control Structures: Radio telescope, antenna dish NO NO
All member loads (USP accepts member loads on ELEM TRUSS in addition to self-weight load generation in any direction to be powerful.) YES/NO ?
  • Verification: Meaningful examples to convey the important features.
    (Most of them 3-D structures)
    		• NO such example except fake examples
  • A college sophomore or junior student can check, verify and be convinced.
    		• If provided, YES but hard since it has NO ready Global Coordinate Output. YES
    (some HARD ?)
    1. JOINT STATIC EQUILIBRIUM(From Joint(Global) Coordinate OUTPUT)
    2. STRAIN vs STRESS COMPATIBILITY of A TENSION-ONLY MEMBER
      a) STRAIN:
      • From Original Input, you get original length.
      • From Joint(Global) Coordinate OUTPUT, you get Joint Displacements and strained length.
      b) FORCE: From Element Local Coordinate OUTPUT.
      c) CHECK:
      • TENSION: It follows HOOK's LAW
      • COMPRESSION: It follows HOOK's LAW up to Euler critical buckling load.
  • JOINT STATIC EQUILIBRIUM: For a joint to which Zero Compression Members link, you can tally and sum up at this joint all forces that are (input to it and) output from all elements in a given, say; Y-direction.
    Frequently forces that are associated with the Zero Compression Members, unlike those by U S P, are NOT listed in the output. If so, the Joint is NOT in eqilibrium due to the fact the external loads on the members are not accounted for.
    The equilibrium forces from the Members are by simple statically determinate end reaction. (normally 50 % of member loads; see (5) of Column II below.)
    You can hand calculate to check easily.
  • COMPATIBILITY: YES (zero compression)
    • All in ONE INPUT and ONE OUTPUT
    (Unlimited load cases including temperature variations and
    lack-of-fit-in-length load cases.)
  • (1) Treat it as a two-way truss like any other plain programs for a load case. On 1st output, manually study the results. Delete each and every member in compression.
    		• NO. (LOAD COMBINATIONS ?)
  • (2) Reinput and get 2nd output. Redo the 1st output manual process to delete each and every member in compression. Study manually the previous-cycle deleted each and every member on its two end joints. If they displace APART from each other, the corresponding member must be put back. This is for a nominal load case that does not include temperature variations and/or lack-of-fit-in-length (mal-maunufacturing) situations. In this case, simple APART-or-not is NOT good enough a criterium. It has to take into account of REAL ZERO compression length. (A bigger manual job)
  • (3) Reinput and get 3rd output. The manual process as indicated above must be repeated for the next reinput. This processes must go on and on.
  • (4) Until such time when all members that were left in are in tension and all those deleted members for which the two end joints displace NOT apart. (See (2) for more complicated criterium.)
    		• DONE internally by computer
    NO PROBLEM
  • (5) Problem: For the given loading condition, the loads (dead load, snow/ice load, wind load and/or live load) on those deleted members have not been accounted for during the above manual input-output cycles.
    		• Problem exists ? You as a user can find out byJoint Static Equilibrium.
    with PRECISE RESULTS
  • (6) To do a correct job, they must be included and the man-power requirement is to be even more in term of manual human error and quality control. This is an impossible task.
    		• INCORRECT RESULTS THERE if above is true?
    Another loading case: ONE additinal simple load case within the same input set. Another loading case: a big manual input-studyoutput-reinput CYCLES like the one previously ONE additional load case within the same input set. (Frequently total load cases are limited.)
    LOAD COMBINATIONS: 1   1.4    2   1.7
    (Say; 1.4 times Load Case 1 and 1.7 times Load Case 2)
    (O K and powerful)     		LOAD COMBINATIONS: 1   1.4    2  1.7
    This Command can NOT be used.
    For every combination, you must manually compute the load initially and treat them as one simple load case. An even bigger man-computer input-output cycles are needed because loads on deleted members in all likelihood must be accounted for.
    Otherwise, the results will NOT be useful in engineering.     		NOT ALLOWED ?
    Oblique Planar Joints: As many as feaseable to stabilize the direction normal to each/every plane NO. (This is Critical.)
    Fall Back:Introduce a small member for each planar joint.
    RESULT: Approximate analysis ?     		YES/NO ?
    If NO, same as in column II. (NOT too good)
    TRUE MEANINGFUL EXAMPLES provided with COMPLETE input and output that can be checked easily as mentioned above. EXAMPLE PROBLEM NO. 4: Truss Structure with Tension Bracing- A simple 2-D structure that requires an engineer to make a pre-judgment to delete tension-only members (3 of 6 diagonally directed towards left; the other 3 towards right) that are directed with compressive component against simple joint loads direction. Practically all engineers can make that judgment and all programs can do the analysis. That kind of simple structure practically does not exist in real engineering world-
    An example to confuse the public.
    A 3-D complex structure can not be pre-judged by practically any engineer.
    Conclusion: You as an end user can help police the bad apple by uncovering more of MISREPRESENTATION.

    NOTE: ? mark indicates that CAEinc believes strongly with professional opinion to be correct/nearly-correct. You as a user shall find out to be 100 % absolute or not. CAEinc will verify for you without charge by analyzing your runs if you will provide the Input and Output data of the runs.


    This one below is a deliberate act to MISREPRESENT a very ordinary plain Program as a Powerful Program to the public   vs                                CAESETS to the rignt ===> ===>.
    It has nothing to do with program bugs.   CAEinc believes that Research Engineers as Johny-coming-lately must have come cross CAEinc's leaflets of tension-only bracing capability long before it started after MSDOS arrival to the industry in late 1970.
    If it is too big for you     click here for reduced scale.

    File misrepst.gif

    BACK IN 1970 POWERFUL REAL PRACTICAL ENGINEERING CAPABILITY
    with BREAK-THRU IN THEORY File trnstowr.gif

    Structure - Programming - Vibration - Foundation - Civil

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    September/15/1999,Nov. 13, 2004 and Oct. 12, 2023     .