Advanced test methods of material property characterization:high strain-rate testing and experimental simulation of multiaxial stress states

Optimum utilization of the loading capability of engineering materials is an important and active contribution to protect nature's limited resources,and it is the key for economic design methods.In order to make use of the materials' resources,those must be known very well;but conventional test methods will offer only limited informational value.The range of questions raised is as wide as the application of engineering materials,and partially they are very specific.The development of huge computer powers enables numeric modelling to simulate structural behaviour in rather complex loading environments-so the real material behaviour is known under the given loading conditions.Here the art of material testing design starts.To study the material behaviour under very distinct and specific loading conditions makes it necessary to simulate different temperature ranges,loading speeds, environments etc.and mostly there doesn't exist any commonly agreed test standard.In this contribution two popular,non-standard test procedures and test systems will be discussed on the base of their application background,special design features as well as test results and typically gained information:The demand for highspeed tests up to 1000 s^(-1) of strain rate is very specific and originates primarily in the automotive industry and the answers enable CAE analysis of crashworthiness of vehicle structures under crash conditions.The information on the material behaviour under multiaxial loading conditions is a more general one.Multiaxial stress states can be reduced to an equivalent stress,which allows the evaluation of the material's constraint and criticality of stress state.Both discussed examples shall show that the open dialogue between the user and the producer of testing machines allows custom-tailored test solutions.

DE based economic control chart design and application for a typical petrochemical process

Petrochemical industry plays an important role in the development of the national economy. Purified terephthalic acid(PTA) is one of the most important intermediate raw materials in the petrochemical and chemical fiber industries. PTA production has two parts:p-xylene(PX) oxidation process and crude terephthalic acid(CTA) hydropurification process. The CTA hydropurification process is used to reduce impurities, such as 4-carboxybenzaldehyde, which is produced by a side reaction in the PX oxidation process and is harmful to the polyester industry. From the safety and economic viewpoints, monitoring this process is necessary. Four main faults of this process are analyzed in this study. The common process monitoring methods always use T^2 and SPE statistic as control limits. However, the traditional methods do not fully consider the economic viewpoint. In this study, a new economic control chart design method based on the differential evolution(DE) algorithm is developed. The DE algorithm transforms the economic control chart design problem to an optimization problem and is an excellent solution to such problem. Case studies of the main faults of the hydropurification process indicate that the proposed method can achieve minimum profit loss.This method is useful in economic control chart design and can provide guidance for the petrochemical industry.

Design framework for robotic surgery wards at hospitals:Computational implementation

Robotic surgery is one of the most recent technologies in healthcare building field.Due to the design complexity of Robotic surgery wards,computational implementations are being developed to either measure the effect of inserting advanced technologies as Electronic medical recorders and tele surgery,or evaluate design alternatives on healthcare building.This paper presents a design framework that responds to the need for coordinating design phases for Robotic Surgery Wards(RSWs)computationally.This proposed design framework for RSWs can generate functional RSW alternatives and more than one solution for each alternative.The framework has been structured based on the main architectural considerations of RSWs which are geom etric and topological,the economic considerations,specific developed pools for shape and corridor patterns,and the theory of,fShape Grammars"has been utilized to compute the framework to generate a vast number of design alternatives.Accordingly,a computational implementation has been established to assist designers in early design stages.Numerical validation for the applications of the developed framework and implementation has been conducted by using reference examples of RSWs.The main finding in this paper is providing healthcare building designers with a computational implementation that generates RSW alternative computationally based on specific shape and cost levels.