Materials

100問 • 2年前

問題一覧

involve interdisciplinary activities with contributions from different segments of an industrial enterprise including design, materials and manufacturing, finance, legal, sales, and marketing. This is because in addition to satisfying the technical requirements, a successful product should also be esthetically pleasing, safe to use, economically competitive, and compliant with legal and environmental constraints.

Product Design and Development

7 stages of product and development

1. IDENTIFICATION OF NEEDS, FEASIBILITY STUDY AND CONCEPT SELECTION 2. SYSTEM-LEVEL DESIGN, DETAIL DESIGN AND SELECTION OF MATERIALS AND PROCESSES, 3. TESTING AND REFINEMENT, 4. MANUFACTURING THE PRODUCT 5. LAUNCHING THE PRODUCT 6. SELLING THE PRODUCT, AND 7. PLANNING FOR ITS RETIREMENT.

A statement describing the function, main features, gener shape, and essential fea- tures of the product is normally followed by a feasibility study that addresses market environment, customer views, technical specifications, economic analysis, as well as social, environmental, safety, and legal issues.

Feasibility Study, Identification of needs, and Concept Selection

involves a survey to evaluate competing produgs and their n characteristics in addition to identifying the customer needs.

Market Research

Identification of needs and customer views is an important first step in the development and design of a new product.

Customers Needs and Product Specifications

is a structured process for translating customer requirements and market research into quantifiable product characteristics and specifications to be met by the product design.

House of Quality

Product specifications are then used to develop different product concépts that satisfy customer needs. Some of the concepts may be generated by the development team as novel solutions but others may be based on existing solutions or patents. The different concepts are then compared in order to select the most promising option

Concept Generation, Screening and Selection

method useful as an initial concept screening tool.

Pugh Method

constructed in Pugh Method where each of the characteristics of a given concept is compared against a base/reference concept, and the result is recorded

decision matrix

provides an economic model that estimates: the development costs, the initial investment that will be needed, the manufacturing costs, and the income that will result for each of the selected concepts.

Economic Analysis

estimates sources and cost of financing based on the rate of interest and

Economic Analysis

Final stage of the feasibility study identifies an optimum solution

Selecting an Optimum solution

helped combine each team members ideas and concepts in order to come up with two designs to continue with which were both better than the original team design.

Concept - Screening Matrix

is usually based on economics as well as technical specifications, since the product is exper to satisfy the customer needs at an acceptable price.

Selection

It should be acceptable not only to the consumer of the product but als the society in general.

optimum solution

The exploration of and decisions about what the components and subsystems are and what their function will be; the basic geometry of the different pieces and how they will be arranged, including location, orientation, and grouping; and how the pieces will connect or interface together and with the environment.

System-Level Design

focuses on aesthetics, user interface, ease of use, and safety features

Industrial design

focuses with the level and type of technology on which it is based, performance, efficiency, energy consumption, and environmental issues.

Engineering Design

represented by blocks.

product architecture

are divided into subsystems or subassemblies, each performing a part of the product's overall function.

Complex products/ systems

made to determine if a subassembly is manufactured specifically (in-house) or if a standard alternative is available (to purchase).

make- or - buy decisions

translated to system-level design, describing the product's appearance, architecture, and technical specifications.

Product Specifications

the focus is on static and dynamic forces and their effect on the performance of the component under the expected service conditions.

Detail design and Selection of Materials and Processes

represent an important part of each phase of the design process. They provide an opportunity to identify and correct problems before they can seriously affect the successful completion of the design.

Design Reviews

a phase is normally carried out as part of the R&D function of the company

Testing and Refinement

are tested to ensure that the product works as intended and that it satisfies its main requirements. Built from parts with the same geometry and material as the final product but not necessarily using the same manufacturing processes

Alpha prototypes

may be built to ensure reliability of the product and to mea sure its level of performance.

Second prototype

covers the activities of planning and scheduling, manufacturing the product, marketing, and arranging for after-sales services. This stage is best organized on the basis of planning and scheduling schemes, which are drawn to meet the product delivery times, as discussed in this section.

Launching the product

To avoid delays and in view of the complexity of many of the engineering projects, planning and scheduling should play an important role in project development.

Project Planning and Schedule

The _____ step in planning is to identify the activities that need to be controlled. The usual way to do that is to start with the entire system and identify the major tasks.

First

describing the activities of installing and preparing

Bar Chart

defined as the creation of new products, either from raw materials or components.

Manufacturing

represents an important activity in manufacturing. It could vary from 100% inspection of produced parts to statistical sample inspection, depending on the application and the number of parts produced. In some applications, it may be necessary to test subassemblies and assemblies to ensure that the product performs its function according to specifications.

Quality control

been an integral part of society for centuries and this looks to continue for as long as humans need products ranging from food and clothes to vehicles and pharmaceuticals.

Manufacturing

is meant to protect the finished product during its shipping to the consumer. Secondary functions of packaging include advertising and sales appeal, which are important aspects of marketing the product, especially in the case of consumer goods

Packaging

Continues to be an import aspect of industry, not just to provide goods for the marketplace, but also to drive the economy. As manufacturing processes continue to advance, so the skills required have also developed, with this trend set to continue in the future.

Manufacturing

The _________ should be involved in the various stages of product development to allow them to develop the publicity material that will help in selling the product. In addition to publicity material, installation and maintenance instructions need to be prepared and distributed with the product. Clear installation, operation, and maintenance instructions will make it ea for the user to achieve the optimum performance of the product.

Marketing Personnel

Most products require either regular or emergency service during their useful life. The accuracy and speed of delivering the needed service and the availability of spare parts could affect the company's reputation and the sales volume of the product.

After- sales service

an important factor to be considered in making an improved version of a product and in developing a new product.

Feedback

In a free enterprise, the price of goods and services is ultimately determined by supply and demand.

Selling the Product

shows the relationship between the quantity of a product that customers are willing to buy and the price of the product.

demand curve

shows the relationship between the quantity of a product that vendors will offer for sale and the price of the product.

supply curve

The intersection of the two curves determines both the _______ and ______in the free market.

n and p

is meant to-compete directly with the existing products.

Product

is already established, and the problem is to work backward from it to determine the cost of each of the product elements.

Selling price

An understanding of the elements that make up the cost of a product is, therefore, essential in ensuring that the product will be competitive economically as well as technically. This means that the selling price has to be low enough to be competitive but sufficiently high for the company to make a profit.

Design to cost

The ____________ is usually charged to the number of products to be sold within a given period. Each department has direct labor and overhead rates per hour for each class of work charged to the product.

Cost of Product Engineering

a failure under mechanical loading where Manufacturers are using materials closer to their limits of performance, which increases the probability of failure.

Increasing performance pressure

a failure under mechanical loading where Using stronger materials can reduce weight but increases the tendency for buckling and brittle fracture.

Effects on stronger materials

a type of failure under mechanical loading where Engineering materials have established ranges of applications and exceeding them could lead to failure.

Materials capabilities

a failure under mechanical loading where Underutilizing material capabilities results in uneconomic products.

Conservative approach

This chapter discusses the causes of different types of failures under mechanical loading and ways to avoid them

Types of failures

type of mechanical loading that subjects the material to stresses, which, if sufficiently high, can cause yielding of the component material.

Static loading

a mechanical loading which can cause fracture of a component if the amount of energy it delivers is higher than the toughness of the material.

Impact loading

a mechanical loading that can cause failure by fatigue fracture, especially in the presence of material defects or stress raisers

Alternating and fluctuating loading

type of mechanical loading that Causes the Material to Creep When the creep strain exceeds allowable tolerances, it can cause interference of parts. - In extreme cases, failure can occur through the ______ of the component subjected to creep. - In bolted joints and similar applications, failure can occur when the initial stressing has relaxed below allowable limits, resulting in loose joints or leakage.

High Temperature loading,rupture

a type of loading that Causes wear in the material - Excessive wear can lead to unacceptable play in bearings and loss of accuracy of movement.

Friction and Abrasive loading

Other types of wear failure include galling and seizure of parts - ____ is primarily a surface phenomenon

Wear

3 effects of imperfections in component materials

1. Types of Imperfections 2. Local Stress Concentrations 3. Fracture Roughness

Types of Mechanical Loading

Static, Impact, Alternating and Fluctuating, High Temperature, Friction and Abrasive

Imperfections can cause local stress concentrations, impacting the performance and integrity of components.

Local Stress Concentrations

Engineering components can contain potential sites for cracks in the form of discontinuities, heterogencities, flaws, inclusions, or microstructural defects.

Types of imperfections

Predicting the fracture strength of a component requires knowledge of both the severity of the stress concentration and the fracture toughness of the material.

Fracture Roughness

are used to determine the flaw size, orientation, and distribution in components

Flaw Detection

Enumerate the non destructive methods of crack detection

Visual Examination Penetrant Test Radiographic Examination Magnetic Particle Method Ultrasonic Tests Eddy Current Inspection

liquids that enter surface discontinuities by capillary action are first applied to the surface and then wiped off. A developer is then applied to help delineate the areas where the liquid has penetrated.

Penetrant Test

- X-rays and y-rays are used to penetrate materials and are then caught on a sensitized film. Cavities or inclusions absorb the rays differently from the rest of the material and are delineated on the developed film.

Radiographic Examination

- a liquid containing iron powder is first brushed on the surface, and the part is then placed in a strong magnetic field. The particles pile up at discontinuities.

Magnetic Particle Method

- ultrasonic vibrations that are transmitted through the material are reflected back at an internal discontinuity earlier than when reaching the opposite surface. The difference between the reflected waves is used to locate the position of the discontinuity.

Ultrasonic Tests

Application: Radiographs show the size and shape of discontinuities (ASTM E 94)

Radiographic Examination

Application: Detects surface cracks in magnetic materials (ASTM E 109 and E 138)

Magnetic Particle Method

Application: Internal defects in ferrous and nonferrous metals and alloys (ASTM E 127)

Ultrasonic Tests

- a coil is excited to induce eddy currents in the component to be inspected. In turn, this excitation induces a current in the coil. The presence of defects affects the induction of the component, which affects the current in the coil.

EDDY CURRENT INSPECTION

Application: Used for the inspection of surface and subsurface defects in electrically conducting materials

Eddy Current Inspection

are commonly used for transmitting motion and power to shafts with short center distances, and may be operated with small pulley diameters

V-belt drives

drive a power transmission device, which consists of one or more V-belts, mounted two or more V-pulleys

V-belt

Majority in the Philippines uses machinery that have?

V-belts and Flat belts

Engineering Materials - V-belts and Pulleys for Agricultural Machines - Specifications Band Applications

PAES 301

a wheel with one or more grooved rims used to transmit motion and power by means of one or more V-belts

v-pulley

- a type of machinery that produces good quality corn grits

Mobile Corn Mill

a type of huller composed of feeding, husking and separating the coffee bean and impurities

Coffee/Cacao Dehuller

a heavy duty machine that separates coco fibers (coir/ cocopeat) from coconut husk through crushing action from a conveyor to sieve.

Coco coir Processing Machine

a type of crusher that can grind, pulverize, crush various commodities specially corn livestock feeding.

Hammer Mill Grinder

a machine that cuts or slices cassava that produces fine chips suitable for high quality cassava flour productions.

Cassava Chipper

2 types of v-pulley

1. Single grooved 2. Multi grooved

True or False A v- belt is constructed of cords (cotton, rayon, synthetic, or steel) and fabric impregnated with rubbers

True

- The following information shall be marked on the V-belt:

Manufacturer’s name, trademark and Type of cross section and pitch length

In designing belt drives, it should be recognized that the use of ____ pulley diameters will rest in ______ bearing loads and can result in the use of smaller and less expensive belt cross-section

larger, lower

Formula of length calculation

L= 2C + pi/2 (DL+DS) + (DL-DS)^2/4C

In length calculation, these values means: L C Ds DL

Length of the belt distance between center pulleys pitch diameter of small pulley pitch diameter of large pulley

Center distance calculation formula

C= b + square root of (b^2 -33(DL-Ds)^2 / 16

value of b in center distance calculation

4L - 6.28 (DL + Ds)

Used to Transmit rotary motion and power between two shafts, which flat on the face of its corresponding pulley

flat belt

I will having flat or crown face used to transmit motion and power by means of flat belts

flat belt pulley

A power transmission device used to transmit power and motion between two shafts, consisting of flat belts which ride in flat pulley

flat belt drive

Outside diameter of the pulley

pulley diameter

Stretch out length of the belt

belt length

Ratio of the angular velocities of the police, making no allowance for slip and creep

speed ratio

The linear speed of the belt calculated by multiplying the RPM and the diameter of the driver, pulley and to the value of pi

belt speed

100

PAES 302 is named?

Engineering Materials- Flat belts and Pulley for Agricultural Machines- Specification and Applications

Materials 1.2

ユーザ名非公開 · 66問 · 2年前

Materials 1.2