CAD of cushioning packaging with maximum accelerat

CAD of cushioning packaging with maximum acceleration static stress curve

Abstract: [i starting from the process of cushioning packaging design, this paper systematically puts forward the problems that should be paid attention to in the development of cushioning packaging CAD software, focuses on how to make the developed software convenient for users' operation, adjustment and modification, and gives an understanding of some difficult links to support the dual experimental mode of peeling and stretching; the solution provides a feasible idea for the development of cushioning packaging CAD software. Reduce and eliminate plastic packaging materials Pollution and impact on the ecological environment [/i

key words: [I buffer packaging CAD coding curve fitting [/i

the design of buffer packaging is one of the important components of the protection function of packaging. However, at present, in the process of buffer packaging design of products, the selection of buffer materials and the calculation of size not only need to check many diagrams and tables, but also need to spend a lot of time on calculation, analysis and comparison. The design process is very cumbersome and the amount of calculation is quite large. If you use computers to deal with these complex calculations, buffer packaging design It will become very simple. As long as you input some necessary parameters as known conditions, the computer will help you design the size and material of the cushion. This module should include the following five parts: parameter input; Similar buffer packaging scheme retrieval; Cushion pad design; The result is to shorten the residence time output part; Database maintenance (as shown in Figure 1)

1. Parameter input

parameter input of buffer packaging program includes: product characteristics and circulation conditions

1) product characteristics: product quality, product shape, product size (length, width, height or height, diameter), product brittleness value. If there is a critical element, enter the brittleness value, natural frequency and damping coefficient of the critical element

2) circulation conditions: mainly including transportation mode (highway, railway, waterway, air transportation and combined mode) and loading and unloading mode (manual loading and unloading, mechanical loading and unloading and combined loading and unloading mode)

2. Similar buffer packaging scheme retrieval

the main function of the similar buffer packaging scheme retrieval part is to retrieve the buffer packaging design scheme similar to or corresponding to the conditions in the buffer packaging scheme parameter table and buffer packaging scheme table based on the relevant conditions entered by the user from scratch, so as to prevent repeated design and save design time

the general idea of the retrieval of similar buffer packaging scheme: according to the input parameters, code in a certain way to obtain its combination code. The DAO database technology is used to access the "buffer packaging design parameter table" in the "packaging design database", and the records with the same or similar combination code and the input parameter combination code are queried, and the "buffer packaging design scheme table" is accessed according to the primary key of the record. The form of parameter table is shown in Table 1, and the scheme table is shown in Table 2

3. Cushion pad design

this part is the core part, mainly based on the input design conditions, using the design theory of minimum value and optimization design principle, the computer automatically selects the qualified local cushion pad materials, calculates the design parameters such as thickness and area, and checks the performance of the designed cushion. The algorithm and verification of using the maximum acceleration static stress curve have been explained clearly in some textbooks, and will not be discussed here. It mainly explains the following points:

(1) determination of equivalent drop height

(2) data processing of maximum acceleration static stress curve

the curve cannot be designed according to the curve in computer-aided design, so the curve is functionalized. According to the characteristics of the maximum acceleration static stress curve, the curve can be approximately fitted into a quadratic curve by the least square method, and its function is expressed as (equation 4):

in order to calculate the maximum acceleration according to the stress. Other curves can also be treated in a similar way

(3) adjustment of results

the schemes designed by using the above principles may not be very satisfactory to users, which requires that the developed software should be convenient for users to modify, mainly considering the following aspects: ① local and comprehensive switching. It may be more reasonable to use full buffer for some products, so it is convenient for users to change between local buffer and full buffer. ② The re selection of liner materials, when users do not have computer-aided design materials, in order to use existing materials for design. ③ Thickness adjustment: when the designed pad area is too small or too large, the area can be adjusted by changing the thickness. This thickness must be adjusted between the thicknesses with characteristic curves, that is to say, the thickness is not entered randomly, but selected from the given thicknesses

4. Output results

the output should include the input parameters (product characteristics, loading and unloading mode, transportation mode), pad material, material density, buffer packaging method (local buffer and overall buffer), pad structure (corner pad, flat pad, edge pad or other pad structure), pad thickness, effective area of the pad, etc

in order to facilitate users to modify and adjust the output format, it is best to output the results in word. If you use VC to develop this software, you need to add some classes contained in the B file in the office software to your project, and then write the program code imported into word to complete the function of output as word document. Of course, there are other processing methods, which will not be introduced here

5. Database maintenance

with the development of packaging technology and the emergence of new cushioning packaging materials, the software also needs to be constantly modified. If the maintenance module of the database is developed reasonably, we don't need to change the code of the program, just add some characteristics of new materials to the database. This not only facilitates the use of users, but also extends the life of the software

a successful software must be convenient for users to operate. Of course, buffer packaging aided design software is no exception, so