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How To Crack Cmh Softwarr4/21/2021
But he appeals to standards and expectations set by the National Center for Advanced Materials Performance (NCAMP, Wichita, KS, US), which works with the US Federal Aviation Admin. (FAA, Washington, DC, US) and industry partners to qualify material systems and CMH17-1G, the latest revision of the Composites Material Handbook.However, the trade-off is that thousands of physical coupons are required at the materials level (bottom).
Rousseau says simulation is used in analysis and modeling validation at the subcomponent, component and full-scale levels. VA tools use physical lamina test data at 0, 90 and 45 to build laminate test coupons using finite elements and virtual testing to calculate laminate properties. Physical laminate testing is only performed at the red dots to validate results. Critics of the building block approach (BBA) used to generate design allowables claim that the required testing of thousands of physical coupons at the materials level (Fig. Opponents contend that the majority of BBA cost is not in coupon testing but, instead, in component and full-scale tests, and that these levels are where the progressive damage analysis (PDA) that undergirds virtual allowables (VA) offers more benefits. Further, they argue that physical testing is, in any case, currently an aircraft certification process requirement. Lockheed Martin Aeronautics (Fort Worth, TX, US) senior staff engineer and stress analyst Dr. Carl Rousseau defended conventional building block practice as the author of Why virtual allowables are not cost-effective. Rousseau believes physical testing is the best method for quantifying variability in constituent fibers, resins and manufactured laminates. Assaker asserts variability is easily simulated by using the deviation in fiber and resin properties per manufacturers data, while laminate defects from processing can be included in the models and explored via PDA simulations. Each has respect for the others position, and though they see value in comparing the time and cost of the two approaches, each contends that his position in such comparisons is often misrepresented with incorrect supporting numerical data that needs to be clarified. Details and subcomponents are two-thirds of the remainder, so coupon testing may total US500,000 per material. In other words, unlike metal, a composites properties vary based on laminate stacking sequence, lotbatch properties of fiber and resin, laminate manufacturing molding process, environmental conditions, etc. Why add uncertainty by modeling when you can physically test to prove and bound actual variability. Instead of testing every part of every structure, the idea was to establish material basis values and use these to calculate preliminary design allowables. Then, based on the structural analysis, critical areas were identified for physical test verification. Thus, by testing greater numbers of cheap, small specimens, large-scale tests were minimized. Technology risks were assessed early in the program and analyses traditional closed-form (i.e., hand-calcs) and, over time, finite element and other computer methods were used in place of tests where possible. At all different stages and scales of development, both testing and simulation are used, says Rousseau (Fig. We agree that more of the cost is in the full-size articles testing, he says. However, we estimate US5.7 million for all testing to generate allowables for a completely new material Fig. Only for materials that are well known, he emphasizes, can you reduce the cost as Rousseau asserts on p. US500,000. Our approach for a new material is to reduce the US5.72 million to US476,500 for statistical physical testing, and do the rest via simulation. But he appeals to standards and expectations set by the National Center for Advanced Materials Performance (NCAMP, Wichita, KS, US), which works with the US Federal Aviation Admin. FAA, Washington, DC, US) and industry partners to qualify material systems and CMH17-1G, the latest revision of the Composites Material Handbook.
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