Comparison between computed and measured fibre orientation in injection moulded parts

International audienceShort fibre reinforced thermoplastic materials play an important role in automotive industries due to their excellent processing behaviour, reasonable good mechanical performance, high design freedom and cheap prices. Although the thermo-mechanical requirements for the materials used increase the development cycles decrease. Numerical simulation, FEA, analysis can be a strong assistant when judging designs and reducing cost and time consuming experimental tests. The mechanical properties for short fibre reinforced thermoplastics are mainly dominated by fibre orientation which results from injection moulding process. Several commercial tools offering 3D flow simulation are on the market, each of them with strengths and weaknesses and a lot of opportunities for future application in part design. In cooperation with Ecole Nationale Superieure des Mines de Paris a study was carried out in order to compare two different injection moulding simulation tools (MOLDFLOW MPI® and REM-3D®) with experimental data concerning fibre orientation prediction. The study contains investigations on the accuracy and sources of measurement errors on the well-established surface ellipse method on polished surfaces and gives an overview on the state-of-the art in this field. On the other hand simulation results compared with measurements on a sample geometry taken at different locations indicate that the accuracy of the simulation needs some improvement, too. Areas of fairly good agreement and those of significant differences are discussed. The importance of accurate fibre orientation on subsequent thermo-mechanical analysis is stressed out by comparing experimental data with simulated deformation behaviour. As a conclusion, alternatives both for experimental setup and algorithms used for the numerical prediction of fibre orientation so far based on the well-known Folgar-Tucker model are proposed. The limitations of this model for real parts will be discussed for this purpose

ФУНКЦІОНАЛЬНИЙ СТАН ЩИТОПОДІБНОЇ ТА ПАРАЩИТОПОДІБНОЇ ЗАЛОЗ У ДІТЕЙ З ЕКОЗУМОВЛЕНИМИ ОСТЕОПАТІЯМИ.

We investigated the functional state of thyroid and parathyroid glands in 227 children with ecologically determined bone diseases. Triiodothyronine, thyroxin, calcitonin and parathormone level of these children was determined by immunoreactive method. Bone mineral density and bone system degree of changes were measured by ultrasound densitometry: bone mineral density < 67 % - osteoporosis, bone mineral density from 80 % to 67 % - osteopenia, 100 +/- 20 % - normal bone mineral density, 120 % and more - osteosclerosis. Parathormone level was significantly decreased in all children with osteoporosis and osteopenia from ecologically polluted regions. Subclinical hypothyroidism is a marker for radiation polluted environment, and subclinical hyperthyroidism is a marker for chemically polluted environment.Был исследован функциональный статус тиреоидной и паратиреоидной желез у 227 детей с экозависимыми остеопатиями. Иммунореактивным методом исследован уровень трийодтиронина, тетрайодтиронина, кальцитонина и паратгормона у этих детей. Методом ультразвуковой денситометрии определена минеральная плотность костной ткани (МПКТ): меньше 67 % - остеопороз, МПКТ от 80 до 67 % - остеопения, нормальная МПКТ - 100 +/- 20 %, 120 % и более - остеосклероз. Уровень паратгормона был существенно снижен у детей с остеопорозом и остеопенией из экологически загрязненных регионов. Субклинический гипотиреоз является маркером для радиационно загрязненных регионов, а субклинический гипертиреоз - маркером для химически загрязненных регионов. Було досліджено функціональний статус тиреоїдної та паратиреоїдної залоз у 227 дітей з екозалежними остеопатіями. Імунореактивним методом досліджено рівень трийодтироніну, тетрайодтироніну, кальцитоніну та паратгормону в цих дітей. Методом ультразвукової денситометрії визначено мінеральну щільність кісткової тканини (МЩКТ): менше 67 % - остеопороз, МЩКТ від 80 до 67 % - остеопенія, нормальна МЩКТ - 100 +/- 20 %, 120 % і більше - остеосклероз. Рівень паратгормону був суттєво знижений у дітей із остеопорозом та остеопенією з екологічно забруднених регіонів. Субклінічний гіпотиреоз є маркером для радіаційно забруднених регіонів, а субклінічний гіпертиреоз - маркером для хімічно забруднених регіонів

On the valence shell electronic spectroscopy of 2-vinyl furan

The vacuum ultraviolet (VUV) absorption spectrum (3.50-10.33 eV, 350-120 nm) of gaseous 2-vinyl furan has been measured for the first time using both synchrotron radiation source and electron energy loss spectroscopies with absolute cross section determinations. The He I photoelectron spectrum obtained at higher resolution than previously has been interpreted with the aid of semiempirical molecular orbital calculations. Three excited states of type (1)pipi(*) are found responsible for an intense and structured first band observed between 4.2 and 5.8 eV (295-214 nm). Three triplet states were detected for the first time at about 2.46, 3.35, and 3.8 eV (477, 370, and 328 nm) which are, from the calculations, assigned as (3)pipi(*). Some partial Rydberg series, linked to IE1 and IE2 are identified. The VUV absorption spectrum bears little resemblance to that of the parent compound, furan. The electronically excited molecule is found akin to a linear polyene. (C) 2004 American Institute of Physics