Search results

Gives a bibliographical review of the finite element methods (FEMs) applied for the linear and nonlinear, static and dynamic analyses of basic structural elements from the theoretical as well as practical points of view. The range of applications of FEMs in this area is wide and cannot be presented in a single paper; therefore aims to give the reader an encyclopaedic view on the subject. The bibliography at the end of the paper contains 2,025 references to papers, conference proceedings and theses/dissertations dealing with the analysis of beams, columns, rods, bars, cables, discs, blades, shafts, membranes, plates and shells that were published in 1992‐1995.

The Sanitary Committee of a certain County Council, strong with the strength of recent creation, have lately been animated by a desire to distinguish themselves in some way, and, proceeding along the lines of least resistance, they appear to have selected the Public Analyst as the most suitable object for attack. The charge against this unfortunate official was not that he is incompetent, or that he had been in any way negligent of his duties as prescribed by Act of Parliament, but simply and solely that he has the temerity to reside in London, which city is distant by a certain number of miles from the much favoured district controlled by the County Council aforesaid. The committee were favoured in their deliberations by the assistance of no less an authority than the “Principal” of a local “Technical School”;—and who could be more capable than he to express an opinion upon so simple a matter? This eminent exponent of scientific truths, after due and proper consideration, is reported to have delivered himself of the opinion that “scientifically it would be desirable that the analyst should reside in the district, as the delay occasioned by the sending of samples of water to London is liable to produce a misleading effect upon an analysis.” Apparently appalled by the contemplation of such possibilities, and strengthened by another expression of opinion to the effect that there were as “good men” in the district as in London, the committee resolved to recommend the County Council to determine the existing arrangement with the Public Analyst, and to appoint a “local analyst for all purposes.” Thus, the only objection which could be urged to the employment of a Public Analyst resident in London was the ridiculous one that the composition of a sample of water was likely to seriously alter during the period of its transit to London, and this contention becomes still more absurd when it is remembered that the examination of water samples is no part of the official duty of a Public Analyst. The employment of local scientific talent may be very proper when the object to be attained is simply the more or less imperfect instruction of the rising generation in the rudiments of what passes in this country for “technical education”; but the work of the Public Analyst is serious and responsible, and cannot be lightly undertaken by every person who may be acquainted with some of the uses of a test‐tube. The worthy members of this committee may find to their cost, as other committees have found before them, that persons possessing the requisite knowledge and experience are not necessarily indigenous to their district. Supposing that the County Council adopts the recommendation, the aspirations of the committee may even then be strangled in their infancy, as the Local Government Board will want to know all about the matter, and the committee will have to give serious and valid reasons in support of their case.

The purpose of this paper is to present a numerically adaptive finite element (FE) method for accurate, efficient and reliable eigensolutions of regular second- and fourth-order Sturm–Liouville (SL) problems with variable coefficients.

After the conventional FE solution for an eigenpair (i.e. eigenvalue and eigenfunction) of a particular order has been obtained on a given mesh, a novel strategy is introduced, in which the FE solution of the eigenproblem is equivalently viewed as the FE solution of an associated linear problem. This strategy allows the element energy projection (EEP) technique for linear problems to calculate the super-convergent FE solutions for eigenfunctions anywhere on any element. These EEP super-convergent solutions are used to estimate the FE solution errors and to guide mesh refinements, until the accuracy matches user-preset error tolerance on both eigenvalues and eigenfunctions.

Numerical results for a number of representative and challenging SL problems are presented to demonstrate the effectiveness, efficiency, accuracy and reliability of the proposed method.

The method is limited to regular SL problems, but it can also solve some singular SL problems in an indirect way.

Comprehensive utilization of the EEP technique yields a simple, efficient and reliable adaptive FE procedure that finds sufficiently fine meshes for preset error tolerances on eigenvalues and eigenfunctions to be achieved, even on problems which proved troublesome to competing methods. The method can readily be extended to vector SL problems.

The purpose of this paper is to develop and apply an exact finite strip (F‐a FSM) for the buckling and initial post‐buckling analyses of box section struts.

The Von‐Karman's equilibrium equation is solved exactly to obtain the buckling loads and deflection modes for the struts. The investigation is then extended to an initial post‐buckling study with the assumption that the deflected form immediately after the buckling is the same as that obtained for the buckling. Through the solution of the Von‐Karman's compatibility equation, the in‐plane displacement functions are developed in terms of the unknown coefficient. These in‐plane and out‐of‐plane deflected functions are then substituted in the total strain energy expressions and the theorem of minimum total potential energy is applied to solve for the unknown coefficient.

The F‐a FSM is applied to analyze the buckling and initial post‐buckling behavior of some representative box sections for which the results were also obtained through the application of a semi‐energy finite strip method (S‐e FSM). For a given degree of accuracy in the results, however, the F‐a FSM analysis requires less computational effort.

In the present F‐a FSM, only one of the calculated deflection modes is used for the initial post‐buckling study.

A very useful and computationally economical methodology is developed for the initial design of struts which encounter post‐buckling.

The originality of the paper is the fact that by incorporating a rigorous buckling solution into the Von‐Karman's compatibility equation, and solving it, a fairly efficient method for post‐buckling stiffness calculation is achieved.

In its passage through the Grand Committee the Food Bill is being amended in a number of important particulars, and it is in the highest degree satisfactory that so much interest has been taken in the measure by members on both sides of the House as to lead to full and free discussion. Sir Charles Cameron, Mr. Kearley, Mr. Strachey, and other members have rendered excellent service by the introduction of various amendments; and Sir Charles Cameron is especially to be congratulated upon the success which has attended his efforts to induce the Committee to accept a number of alterations the wisdom of which cannot be doubted. The provision whereby local authorities will be compelled to appoint Public Analysts, and compelled to put the Acts in force in a proper manner, and the requirement that analysts shall furnish proofs of competence of a satisfactory character to the Local Government Board, will, it cannot be doubted, be productive of good results. The fact that the Local Government Board is to be given joint authority with the Board of Agriculture in insuring that the Acts are enforced is also an amendment of considerable importance, while other amendments upon what may perhaps be regarded as secondary points unquestionably trend in the right direction. It is, however, a matter for regret that the Government have not seen their way to introduce a decisive provision with regard to the use of preservatives, or to accept an effective amendment on this point. Under existing circumstances it should be plain that the right course to follow in regard to preservatives is to insist on full and adequate disclosure of their presence and of the amounts in which they are present. It is also a matter for regret that the Government have declined to give effect to the recommendation of the Food Products Committee as to the formation of an independent and representative Court of Reference. It is true that the Board of Agriculture are to make regulations in reference to standards, after consultation with experts or such inquiry as they think fit, and that such inquiries as the Board may make will be in the nature of consultations of some kind with a committee to be appointed by the Board. There is little doubt, however, that such a committee would probably be controlled by the Somerset House Department; and as we have already pointed out, however conscientious the personnel of this Department may be—and its conscientiousness cannot be doubted—it is not desirable in the public interest that any single purely analytical institution should exercise a controlling influence in the administration of the Acts. What is required is a Court of Reference which shall be so constituted as to command the confidence of the traders who are affected by the law as well as of all those who are concerned in its application. Further comment upon the proposed legislation must be reserved until the amended Bill is laid before the House.

With reference to the report of the Annual General Meeting of the Pure Food and Health Society of Great Britain, which was published in the February issue of THE BRITISH FOOD JOURNAL, and to the speech delivered by MR. GOSLIN upon the proper handling and purveying of meat, an article which has subsequently appeared in The Standard is of considerable interest. It is pointed out that no one who gives the matter serious consideration can approve of the present methods. “Many years ago Oxford made its protest against carcasses or joints being exposed in open‐fronted shops. It is just possible that when the powers that were objected to and forbade this proceeding they thought more of the æsthetics than the science of it, but they most certainly did a good thing when they took flesh foods away from the contamination of street dust and the variations of temperature that are dependent on every gust of wind or every moment of sunlight or shadow.”

The question of the best commercial method of retailing milk requires to be dealt with from the various standpoints of the different classes of milk vendors.

Because of the extensive use of long‐span structures in modern engineering, much attention has been given to the extent to which ground motion phase‐lags affect the internal forces of such structures. In this paper, this problem is studied from the aspect of random seismic analysis, i.e. the random seismic responses of long‐span structures are explored with the phase‐lags of the ground joints of the structures taken into account. The earthquake is regarded as a stationary random process. Formulae for calculating the random responses of the structural displacements and internal forces are derived. Numerical examples are presented which illustrate some basic features of such random response, and also show that the ground motion phase‐lags have considerable effects on structural safety analysis.

According to a report issued by the Director of the Chemical Laboratory of the Department of Police in Berlin which has reached the Journal of the American Medical Association, some interesting exhibitions of German “culture” in the matter of food frauds have been afforded during the war. We do not know the origin or the justification (if any) of the ancient proverb that there is “honour among thieves.” Evidently, however, even this form of “honour,” if it exists, does not exist among the Huns, since the criminal in the German lines is hocussed by the huckster‐criminal in the German fake‐shop. One of the articles supplied to stimulate the Hun in the doing of those deeds of Hunnish valour peculiar to himself is known as “solid alcohol,” advertised as a substitute for familiar alcoholic beverages, and consisting of cubes of gelatin to which brandy and sugar are supposed to have been added before the mixture has solidified. The directions are to pour hot water on these cubes, whereupon one obtains a sweetish fluid, weak in alcohol, and possessing the objectionable flavour of glue. The longer the cubes are kept the greater is the tendency of the alcohol originally present to disappear by evaporation, so that the supposedly invigorating “solid brandy,” never at any time a representative product, becomes weaker and weaker in alcoholic strength. In some cases the cubes have been replaced by collapsible tubes of semi‐gelatinous mixtures containing some brandy and advertised for use in the same way with hot water. The price of two‐ounce tubes varies from 25 to 35 cents. The alcohol content has gradually been reduced by the manufacturers, and one firm went so far as to introduce brandy substitutes and substances of a “peppery” nature to simulate the “warmth” of a dose of brandy. Painful lesions about the mouth have been reported by Germans on the march who were unable to wash out the disgusting mixture that was sent to them by their friends. Other “substitutes” for alcoholic beverages were found to consist of cubes of sugar coloured with coal‐tar dyes mixed with tartaric acid. Grosslv adulterated coffee and cocoa have likewise been supplied in tablet form. One popular brand was sold at the rate of 12 marks per pound. Coffee has been often replaced by chicory mixed with sugar. 500,000 kilograms of cocoa husks found their way into the market in Hamburg alone. Tablets alleged to be made of dried milk, but being nothing of the kind, have been sent in enormous quantities.

If additional evidence were needed of the connection between food supply and the spread of infectious disease, it would be found in a report recently presented to the Finsbury Borough Council by its Medical Officer of Health, Dr. GEORGE NEWMAN. It appears that in the early part of May a number of cases of scarlet fever were notified to Dr. NEWMAN, and upon inquiry being made it was ascertained that nearly the whole of these cases had partaken of milk from a particular dairy. A most pains‐taking investigation was at once instituted, and the source of the supply was traced to a farm in the Midlands, where two or three persons were found recovering from scarlet fever. The wholesale man in London, to whom the milk was consigned, at first denied that any of this particular supply had been sent to shops in the Finsbury district, but it was eventually discovered that one, or possibly two, churns had been delivered one morning, with the result that a number of persons contracted the disease. One of the most interesting points in Dr. NEWMAN'S report is that three of these cases, occurring in one family, received milk from a person who was not a customer of the wholesale dealer mentioned above. It transpired on the examination of this last retailer's servants that on the particular morning on which the infected churn of milk had been sent into Finsbury, one of them, running short, had borrowed a quart from another milkman, and had immediately delivered it at the house in which these three cases subsequently developed. The quantity he happened to borrow was a portion of the contents of the infected churn.