Abstract: The application of mechanical analysis in the innovative design of the ceramic bowl makes the ceramic bowl more artistic, and also prevents burns and slips. First, the test subjects' fingertip pressure when using the ceramic bowl is measured and counted by sensors, and the force analysis is carried out at the point of contact between the hand and the wall of the bowl, to obtain a fuzzy value of the anti-burn friction coefficient of the material, and then through the human Calculate the percentile of the size of engineering. in order to obtain the size of the bowl lid that is suitable for the human hand. Finally, this is verified by relevant experiments and further optimized by computer three-dimensional modeling and mechanical analysis, the goal is to develop an innovative anti-scald non-slip ceramic bowl provides a link.
Key words: product design, ergonomics, mechanical analysis, anti-scald and non-slip ceramic bowl
In recent years, due to the general attention to product safety, people are placing ever higher demands on the material of bowls. Ceramics has become the first choice for people buying bowls because they are the least harmful to the human body. There are always two sides to the existence of things, and ceramics are no exception. When using ceramic bowls, there are two main problems of anti-scald and anti-slip that need to be addressed urgently.
The most important problem of ceramic bowl scald protection is the problem of ceramic thermal insulation materials. Research on the thermal insulation performance of ceramic materials has a long history, and many studies have been carried out at home and abroad by Nait-Ali et al.  Experimentally analyzed the influence of factors microstructures on the thermal conductivity of ceramics, Schlichting et al.  studied and prepared porous thermal insulation ceramics, Yang Chunyang et al. improved, the mechanical properties of the material have been reduced. Ma Yiping  has developed a thermal insulation coating, but it has certain disadvantages and defects. Xu Ting et al.  have developed nano-SiO2 porous thermal insulation ceramic. Although it has the advantages of low thermal conductivity, light weight , high porosity and good mechanical properties, it does not However, industrialization has been achieved. and the cost is high. Regarding the non-slip problem of ceramic bowls, apart from indirect practical research by bowl manufacturers, targeted basic professional research is still in the empty stage.
Based on the above, it is time to develop a heat-insulating, economical and practical ceramic bowl with anti-scalding and anti-slip properties. Starting from the point of view of mechanical analysis, an innovative design is beingi based on traditional ceramics. bowls and man. Starting from the physiological level, to establish a harmonious relationship between "people and ceramic products" , solving the two main problems of anti-scald and slip, make ceramic bowls integrating decorative and practical, and make ceramic bowls move toward satisfaction. In this direction, develop multi-level users' needs. Through this research and design, it provides valuable and innovative methods and insights for the current and future design and manufacture of burn protection and burn protection. - retractable ceramic bowls.
1. Analysis of the use of ceramic bowls
1.1 Ceramic bowl
Yuan Mei once wrote down a famous sentence in the Suiyuan Notes Dishes List: "Gourmet food is not as good as beautiful tableware", believing that the dishes are more important than the food itself, to emphasize the importance of the design of the dishes. the advantages of soft material and healthy ingredients, and is very popular among users. However, it is also accompanied by problems of brittleness and falling, and the dishes are overheated. It is inconvenient to hold the dishes. Usually, people use gloves or other heat-insulating materials to hold the dishes to achieve the purpose of holding the dishes. It can be seen that the search for ceramic tableware that does not burn and does not slip has become an important issue in the design of ceramic tableware. This reasonable anti-scald and slip protection of ceramic bowls is not only convenient for users, but also contributes to the better development of the ceramic industry.
1.2 Analysis of hand position using a ceramic bowl
Each item interacts with the user in a different way. To carry out different cutlery, different hand positions are required, which is limited by the size and shape of the cutlery. For example, in this position, the grip force of the pads of the five fingers and the center of the palm are used to support the object [Fig. 1(a)]. In this position, there is a small area of scattered point contact between the fingertips and the object. Contacts are the most, therefore, tactile sensations on the fingertips are the most sensitive. Therefore, the sensation of heat in the fingertips is stronger than that of the palm when holding bowl. Hold the bottom of the bowl with your thumb, hold the rim of the bowl with your thumb, hold the mouth of the bowl with your thumb, and hold the bottom of the bowl with your index, middle, and ring fingers while serving the bowl, leaving your palms empty [Figure 1(b)].
When discussing the relationship between hands and ceramic bowls, as shown in fig. 1, the hands are in a relatively static state of supporting and holding objects. Referring to the features and research and analysis of bowls as cutlery, the author based on the relationship between hands and ceramic bowls. The relationship handle position is divided into support and end in the case of one hand.sha with anti-slip coating, suitable for most people and with decorative properties
1.3 Analysis of hand contact points during use
Good drinking utensils should take into account the following factors related to the hand: the shape of the hand when the hand is in contact with the utensil, the tactile sensation of the hand on the utensil, the feeling of pressure on the utensil. on the opponent, etc., each of which is in the design of the drinker, should not be ignored. As shown in Figure 2, when using a ceramic bowl with a “supporting” hand posture, the main contact points are the muscles in the pulp of the finger and palm. Among them, the pulp of the finger is the supporting force, the earthworm, the small abductor thumb and the abductor thumb, as shown in Figure 2. When using the ceramic bowl with the "final" hand position, the main points of contact are the pulp of the thumb and forefinger and the entire palm . This requires that the design be primarily viewed from the bottom of the bowl and the wall of the bowl.
2. Experimental design
2.1 Content of the experiment
2.1.1 Force experiment on the abdominal wall of the fingers
The goal is to analyze the pressure and pressure on the subject's hand when it interacts with the ceramic bowl. During this experiment, objective physiological data of the subject's hand are measured, and quantitative analysis is used to determine the impact. of the subject's fingers on the ceramic bowl Pressure on the wall To facilitate observation of the dynamic characteristics of the hand, a transparent glass bowl of the same size as the ceramic bowl and a net weight of 210 g of the experiment was used. Pour a certain amount of water into it, about 420 g.
2.1.2 Experimental equipment (Fig. 3)
The tests were carried out in a human-machine laboratory, at a suitable room temperature and without noise interference. The experiment used the latest German sensor equipment, including Pliance-x16 data acquisition software and S2005-90, S2005-91 sensor equipment , S2005–92, S2005–93, as shown in fig. 3.
A total of 10 people with a bachelor's degree or higher, including 5 men and 5 men. The average age is 22.43 years. The main object of measurement is the left hand. The hands of the subjects are normal, without any medical defects. history.
2.1.4 Experimental characterization
The whole process of the experiment takes about 15 minutes, including pre-experiment preparation, explanation of the experiment, debugging of the equipment, filling in the questionnaire of the test subject and interview after the experiment for 2 minutes. Record the pressure and pressure of each subject for 10 seconds from each finger. , and test three groups to obtain the pressure and average pressure of each finger of each subject within 10s. The experimental steps are as follows: ① To reduce experimental error and improve test accuracy, expThe experimenter explained attention to the subject in the experiment before the start of the experiment. Subjects, experimental requirements and purpose of the experiment; ② Adjust the subject's hand position to make it the most comfortable state; ③ Tell the experimenter to remain still for 10 seconds when starting recording to prevent three sets of data deviations from affecting the experiment results ④Debug program to reduce errors.
2.2 Experimental results
Accordingly, count the pressure changes in the fingers of 10 subjects during the experiment. The number of experiments is 3 times, with 10 seconds as the statistical unit. If the time is too long, it will easily cause fatigue of the subjects' hands, and if the time is too short, it will be difficult to judge the average hand pressure. The subjects were asked to choose the most comfortable position for holding the bowl. The numbers are from 01 to 10, and the pressure on the wall of the bowl is calculated for 10 subjects, respectively. The measurement statistics are shown in Table 1 and Table 2. To obtain the contact area of each finger, hold the bowl with the fingers covered with green paint in a relaxed state. After mathematical statistics of the data, the numerical range of the contact area of different objects on the wall of the bowl was obtained as shown in Figure 5 .
Record the pulp contact area of each finger as S1, S2, S3, S4, S5. The pulp area of the finger can be viewed as an ellipse. Use a to represent the length of the semi-major axis of the ellipse, and b to represent the length of the minor semi-axis Use formula (1) Get the contact area of each finger. distance of the measured semi-minor axis, Ld measures the diameter of the cup, d is the diameter of the cup XP; [d] is the integer part obtained by taking d; X[d], X[d+ 1] represent the observed values at [d] and [d + 1] respectively. The calculation first obtains the average pressure on the bowl wall from three experiments of each finger, and then the experimental data of ten subjects small Sorting in order from largest to largest, to provide a basis for calculating the coefficient of friction of fingers against the walls of the bowl. Select the type according to the percentile of human body size in ergonomics, use the pressure value of the 5th percentile as the upper limit of the reference basis, and use the 95th percentile. The pressure value in percentile is used as the reference basis for the lower limit, and the data range diThe range of pressure values of each finger on the wall of the bowl is obtained in Table 3, and the range of the contact area of the pulp of each finger is shown in Table 4.
3. Diagram Design
3.1 Analysis of the slip resistance of the contact surface
From the point of view of micromechanics, friction is the process of interaction between molecules on the contact surface of two substances, which produces shear and separation under the action of a tangential external force. Normal pressure and contact area of the contact surface will affect the friction.To increase the friction between the fingertips and the wall of the ceramic bowl and reduce the possibility of the ceramic bowl slipping and breaking, consider combining cross-border materials for an anti-slip design. refer to the integration or grafted to ceramic materials. It can not only compensate for the lack of a single material of ceramic materials, but also enrich the texture of ceramic materials. Silica airgel material is one of the ideal cross-border materials for ceramic bowls. It has a decorative appearance and easily forms a consistent and uniform design with ceramic bowls; secondly, it has good functionality. The silica airgel material included in ceramic bowls can make the hand more compact and not easy to slip. , it has high ductility, good affinity and is easy to process. It can add embossed patterns to the surface to increase friction.
3.1.1 Force decomposition
Fill the bowl used in this experiment with water and measure the positive pressure of each fingertip against the wall of the bowl using the transducer. When the finger acts on the wall of the bowl, three forces act on it: gravity, normal finger pressure and friction, to decompose gravity G, first decompose gravity G into force G1 in the opposite direction of FN and force G2 in the opposite direction of f , according to the effect, and analyze the force acting on the object, as shown in Figure 6. Since the resultant force on the object is in a static state If it is zero, then in the vertical direction: FN=G1=Gsinθ, in the horizontal direction: f=G2=GCosθ, we can get that FN /f=tanθ. Among them, FN represents the positive pressure of the finger on the wall of the bowl, G represents the force of gravity, f represents the frictional force of the finger against the bowl.
3.1.2 Fuzzy determination of the coefficient of friction of anti-slip materials
Determination of the coefficient of dynamic friction of ceramic bowls under maximum gravity. The coefficient of friction is the ratio of the friction force between the surfaces to the vertical force acting on one of the surfaces. The formula can be expressed as F = FNμ, where FN means positive pressure, μ represents is the coefficient of dynamic friction. For this experiment, since the hand is dry during the actualbowl, only the coefficient of friction of the silica airgel material is calculated in this experiment. dry and calculates the friction of each fingertip. The average value of the coefficient is shown in Table 5. The test basis is provided by the "US Underwriters Laboratories" (UL) and the "American Society for Testing and Materials" (ASTM). : when the coefficient of friction μ<0.40 is a very dangerous range, the coefficient of friction is in the range of 0.40≤μ<0.50 is a hazardous environment, the coefficient of friction is 0.50≤μ≤0.60 is the basic safe range, the coefficient of friction μ >0.60 is a very safe range. This test shows that in the dry state silicate gas. The coefficient of static friction between the gel material and the hand exceeds 0.50, which can be considered safe.
3.2 Analysis of anti-burn materials
The anti-scalding material uses silica gel, a new lightweight and porous nanomaterial. With its unique structure and excellent thermal insulation performance, it is widely used in high temperature thermal insulation, adsorption, catalysis, etc.[ 16]. Silica airgel has excellent properties such as low density (0.003~0.5g/cm3), low thermal conductivity (block airgel can have heat dissipation up to 0.012W/(m K)) and other advantages, especially under normal pressure. , the thermal conductivity of silica airgel does not change much with increasing temperature. From a functional point of view, silica airgel has excellent thermal insulation, it can effectively insulate the thermal conductivity of ceramic material, and at the same time avoid dull and cold feeling when the skin directly contact with ceramic material in cold winter. At the same time, the choice of this material can not only reduce the chance of slipping when stacking or moving dishes, but also can avoid the noise caused by the collision of dishes against each other, and also protect the dishes and dining table well.
3.3 Product Design Effectiveness
According to the above analysis, the design intent is clear. Based on the shape and shape elements of the ceramic bowl itself, the texture and color of the anti-burn part, as well as safety and comfort, are designed and processed. of the user, while increasing the visually comfortable and aesthetic. In terms of material, the main body of ceramic bowls is made of living porcelain. Living porcelain can not only sterilize and remove dust and purify the air, but is also the best material for far infrared conversion materials, which can improve the body's water absorption and enhance immunity. There is also an inevitable relationship between color and security, and different colors give people a different sense of security. Red and orange symbolize warmth and celebration, blue and green give people a sense of calm and peace, and gray brings opportunities . This creates a depressing and dreary atmosphere. Considering that celadon and white porcelain are mainstream at presenttime in the dish , anti-burn parts are mostly green and blue. The ceramic bowl with white as the main color brings out the color of the food, while the bowl wall with a graphic design that fits the size of the hand creates a feeling of freshness and safety. In the early design stage, the circuit evaluation is mainly improved based on the subjective evaluation of the test subjects and applied to the next stage of computer-aided design. Among them, before modeling, it is necessary to combine the sizes of the hands obtained in the previous experiment for design, because shown in figure 7. Based on this scheme, the simulation is carried out by computer, and at the same time, material savings must be considered Suitable for the size of the human hand After constant modification and improvement, a relatively reasonable final plan is obtained with a form and function that meets expectations, as shown in figure 8. This design firstly meets the requirements of the shape of the human hand while saving materials, and at the same time, it also provides protection against burns.
To solve the problem of ceramic bowls being hot and brittle, safe, practical, economical and easy to mass-produce ceramic bowls with anti-scalding and non-slip properties have been developed. (1) Based on mechanics and materials science. , the cross method is used to make ceramic bowls. The shape and structure of the bowl are researched and designed, and the research and design plan is consistent with the behavior of the hand (2) Model the range of the hand's movement trajectory, and use this range to obtain the size of the commonly used area. According to the relative position of the finger and experimental specimen, bowl (3) This design expands the performance perspective and space of ceramic product design and provides new reference points and design ideas for the innovative design and production of ceramic products.