Download or read book A Theoretical View on the Stress Analysis of Fully Inflated Parachute Canopies written by William P. Ludtke and published by . This book was released on 1984 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes a theoretical approach to the analysis of the force distribution in fully inflated parachute canopies based upon the inflated gore mainseam shape. Normal and tangential forces for any arbitrary point along the gore mainseam can be determined and the magnitude and location of the maximum normal force and cloth stress evaluated. Methods, criteria, and rationale for calculating the force distributions are presented. Originator-supplied keywords include: Canopy shape, and Pressure distribution.
Download or read book Stress Analysis of a Fully Inflated Ribless Guide Surface Parachute written by H. G. Heinrich and published by . This book was released on 1965 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: A stress analysis of a fully inflated ribless guide surface parachute is presented. The method ia an extension of an earlier publication, which is applicable to the transient state of inflation. However, in view of the normal use of ribless guide surface parachutes, the transient phase is considered to be less important since for the so-called infinite mass cases, the maximum force is considered to occur when full inflation is reached. In general, this analysis can be applied to most canopies having non-triangular gore patterns. A numerical calculation is made for a 12-gore ribless guide surface parachute over a range of pressure loadings, canopy sizes, and cloth types representing practical application.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1985 with total page 1076 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stress Analysis of a Parachute During Inflation and at Steady State written by Helmut G. Heinrich and published by . This book was released on 1965 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: The stresses occurring in the cloth of an opening parachute and at steady state are calculated. The method is based on assumed instantaneous and steady state shapes and related pressure distributions. It is general and may be applied to any type and size of canopy built out of solid cloth. The presented analysis is limited to canopies constructed of triangular gores, but can be extended to other gore patterns. A numerical calculation is made for the Solid Flat, Circular Parachute during the opening and at steady state.
Download or read book The Change of Pressure Distribution on Parachute Canopies During Inflation written by H.-D. Mlzig and published by . This book was released on 1965 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: For a design engineer strength calculation is a prerequisite for completion of design. The parachute designer however encounters great difficulty. Theory provides no means for calculation and almost no data is available of measurements under dynamic conditions to permit adequate strength calculation. The rapidly changing dynamic forces can vastly exceed the steady state forces. Great efforts have been made to predict stresses in a parachute canopy. The latest work for a parachute stress analysis was conducted by H.G. Heinrich and L.R. Jamison [1] and is a great advance. Contrary to former attempts it includes parachute shapes during inflation of the canopy. The great disadvantage of all theoretical attempts is that the actual stress distribution in a canopy is still unknown. No method has yet been found to measure stresses directly in many parts of a canopy.
Download or read book The Legacy of the White Oak Laboratory written by and published by . This book was released on 2000 with total page 542 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of Canopy Shapes and Stresses for Parachutes in Steady Descent written by A. D. Topping and published by . This book was released on 1955 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt: Analytical solutions for the fully inflated shapes of the circular canopies of flat, extended skirt, conical, personnel guide surface, and conical ring slot parachutes in steady descent are given. The solution for the flat canopy uses as a first approximation the Taylor curve, and after taking into account the fullness of the gore, yields a shape having a rounded apex rather than the flat top characteristic of the Taylor curve. The solution for the flat canopy is found to be adaptable to all the other canopies except the conical, even though both the conical ring slot and the personnel guide surface canopies are conical. An entirely new solution is developed for the conical canopy by obtaining a first approximation that neglects gore fullness and then altering this by taking fullness into account.
Download or read book A Theoretical Analysis of the Aerodynamic and Structural Forces Associated with a Ribbon Parachute Canopy in Steady Descent written by Kenneth Kenichiro Muramoto and published by . This book was released on 1983 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Measurement of Parachute Canopy Stress During Inflation written by and published by . This book was released on 1978 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Omega sensor was developed for measuring stress in textile and other flexible materials by the Department of Aerospace Engineering and Mechanics of the University of Minnesota and sponsored by the Air Force Flight Dynamics Laboratory. Two studies were conducted by the University which indicated that the circumferential stresses of inflated parachute canopies indicated by Omega sensors agreed with theoretically predicted stresses and also that the stresses measured by an Omega sensor were not affected by dynamic loading. This particular study deals with an in-house test program, designed to measure the circumferential stresses of a model (five foot nominal diameter) ringslot parachute during inflation and at steady state using modified Omega sensors. Slight modifications to the original Omega sensor had to be made due to complications of the tabs tearing during preliminary testing. Five sensors were attached strategically to the canopy of a ringslot parachute and put through a series of low speed wind tunnel tests. The results are presented in detail and provide for the first time actual measurement of circumferential stresses on the surface of a model ringslot parachute. These results, however, can only present the general trend shown in the parachute's stress distribution and not actual stress values due to the inability to calibrate the sensor while attached to the canopy.
Download or read book NASA SP written by and published by . This book was released on 1986 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stress Analysis of an Opening Parachute Canopy written by Daryl Joseph Monson and published by . This book was released on 1963 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Annual Department of Defense Bibliography of Logistics Studies and Related Documents written by United States. Defense Logistics Studies Information Exchange and published by . This book was released on 1986 with total page 1210 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies of Aerodynamics Dynamics and Stress Analysis of Ribbon Parachutes written by Sandia Corporation and published by . This book was released on 1976 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: The following report describes the continuation of wind tunnel data evaluation as shown in Progress Reports 3 through 14 under Sandia Coropration Contract 63-2241 amd 02-4022, Ref 1 to 13. The data presented in this report are related to disreefing tests of a conical ribbon parachute with 140° included angle, concentric rings, and 25% geometric porosity. The data concerning the canopy profile and pressure distributions will be presented in chronological order starting at the time of disreefing and proceeding through inflation at various time intervals until steady state conditions for the fully inflated parachute are reached. The recorded and derived data recorded and derived data are used to obtain-force time histories which can be compared with a measured force-time recording. Also, so called radial force coefficients are derived which are based on the established canopy profiles and the related pressure data.
Download or read book Parachute Stress Analysis During Inflation and at Steady State written by H. G. Heinrich and published by . This book was released on 1969 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the period from 1965 to 1969, two new methods for stress calculations have been proposed and general remarks primarily concerning the elasticity characteristics of a parachute cloth and pressure distribution have been made. The conservative way of performing a parachute stress snalysis consists of first establishing the geometry of the parachute canopy and then applying a certain pressure distribution. Subsequently, the pressure distribution has been linked to the instantaneous parachute force which can be obtained from an opening shock calculation. In this manner one can possibly obtain closed solutions with a minimum of empirical factors. An example of this approach is presented in detail in the following chapters.
Download or read book Aeronautical Engineering written by and published by . This book was released on 1971 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt: A selection of annotated references to unclassified reports and journal articles that were introduced into the NASA scientific and technical information system and announced in Scientific and technical aerospace reports (STAR) and International aerospace abstracts (IAA)
Download or read book Exploratory Parachute Canopy Stress Measurements at Steady State and During Inflation written by Helmut G. Heinrich and published by . This book was released on 1973 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: At the 4th Aerodynamic Deceleration Systems Conference, 1973, the development of the Omega Stress Sensor and initial canopy circumferential stress measurements were reported. Following the first success, the Omega sensor was tested under conditions of rapid loading. No dynamic effects were recorded at strain rates up to 100% per second. In the further pursuit of experimental stress analysis, initial measurements of radial canopy stress were made, and it was found that at certain locations the radial stress is as high or higher than the circumferential stress. Finally, exploratory tests were made in which circumferential stresses were measured on a 5 ft model parachute during the periods of inflation and at the following steady state. All tests were made under infinite mass conditions. The stresses were measured versus time, and their instantaneous values vary with respect to time and location on the parachute canopy.
Download or read book Stress Measurements in Bias Constructed Parachute Canopies During Inflation and at Steady state written by William L. Garrard and published by . This book was released on 1980 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes the results of an experimental study of canopy stresses in bias constructed solid flat parachutes. Stresses were measured in the warp and fill directions during inflation and at steady state for different values of dynamic pressure. Omega sensors were used to measure stress. These sensors were mounted along the gore center lines so that the warp and fill stress distributions could be determined as a function of distance from the vent. It was found that stresses in the fill direction were substantially larger than stresses in the warp direction.
