One of the most widely used tools in the profession is computer-aided design (CAD) software which enables engineers to create 3D models, 2D drawings, and schematics of their designs. CAD together with Digital mockup (DMU) and CAE software such as finite element method analysis or analytic element method allows engineers to create models of designs that can be analyzed without having to make expensive and time-consuming physical prototypes.
These allow products and components to be checked for flaws; assess fit and assembly; study ergonomics; and to analyze static and dynamic characteristics of systems such as stresses, temperatures, electromagnetic emissions, electrical currents and voltages, digital logic levels, fluid flows, and kinematics. Access and distribution of all this information is generally organized with the use of Product Data Management software.
There are also many tools to support specific engineering tasks such as Computer-aided manufacture (CAM) software to generate CNC machining instructions; Manufacturing Process Management software for production engineering; EDA for printed circuit board (PCB) and circuit schematics for electronic engineers; MRO applications for maintenance management; and AEC software for civil engineering.
In recent years the use of computer software to aid the development of goods has collectively come to be known as Product Lifecycle Management (PLM).
4.9 Social context
Engineering is a subject that ranges from large collaborations to small inpidual projects. Almost all engineering projects are beholden to some sort of financing agency: a company, a set of investors, or a government. The few types of engineering that are minimally constrained by such issues are pro bono engineering and open design engineering.
By its very nature engineering is bound up with society and human behavior. Every product or construction used by modern society will have been influenced by engineering design. Engineering design is a very powerful tool to make changes to environment, society and economies, and its application brings with it a great responsibility. Many engineering societies have established codes of practice and codes of ethics to guide members and inform the public at large.
Engineering projects can be subject to controversy. Examples from different engineering disciplines include the development of nuclear weapons, the Three Gorges Dam, the design and use of Sport utility vehicles and the extraction of oil. In response, some western engineering companies have enacted serious corporate and social responsibility policies.
Engineering is a key driver of human development. Sub-Saharan Africa in particular has a very small engineering capacity which results in many African nations being unable to develop crucial infrastructure without outside aid. The attainment of many of the Millennium Development Goals requires the achievement of sufficient engineering capacity to develop infrastructure and sustainable technological development.
All overseas development and relief NGOs make considerable use of engineers to apply solutions in disaster and development scenarios. A number of charitable organizations aim to use engineering directly for the good of mankind.
模具的出现可以追溯到几千年前的陶器和青铜器铸造,但其大规模使用却是随着现代工业的掘起而发展起来的。
19世纪,随着军火工业(枪炮的弹壳)、钟表工业、无线电工业的发展,冲模得到广泛使用。二次大战后,随着世界经济的飞速发展,它又成了大量生产家用电器、汽车、电子仪器、照相机、钟表等零件的最佳方式。从世界范围看,当时美国的冲压技术走在前列——许多模具先进技术,如简易模具、高效率模具、高寿命模具和冲压自动化技术等,其大多起源于美国;而瑞士的精冲、德国的冷挤压技术、苏联对塑性加工的研究也处于世界先进行列。50年代,模具行业工作重点是根据用户的要求,制作能满足产品要求的模具。模具设计多凭经验,参考已有图纸和感性认识,对所设计模具零件的机能缺乏真切了解。从1955年到1965年,是冲压工业的探索和开发时代——对模具主要零部件的机能和受力状态进行了数学分桥,并把这些知识不断应用于现场实际,使得冲压技术在各方面有飞跃的发展。其结果是总结出了模具的设计原则,并使得压力机械、冲压材料、加工方法、模具结构、模具材料、模具制造方法、自动化装置等领域更新换代,并向实用化的方向前进,从而使冲压加工进入生产优良产品的第一阶段。论文网 模具的历史发展英文文献和中文翻译(9):http://www.youerw.com/fanyi/lunwen_24443.html