CN202368695U - Light-weight platform semitrailer body - Google Patents

Abstract

The utility model relates to a platform semitrailer body, which comprises a bearing shell, a base plate and a support beam, wherein the shell is adhered to the lower surface of the base plate and form a box shape structure with the base plate; and the support beam is arranged in the box shape structure and is connected with the shell and the base plate. According to the platform semitrailer body, the weight of the body is effectively lightened due to the structure and the materials; the body is formed integrally, so that the connection of each part is good, the maintenance times can be obviously reduced, and the service life is prolonged; and the body adopts polymer composites, which can be effectively resistant to corrosion, and have better resistant activities to actions of acid, alkali, salt, most organic matters and microorganisms.

Description

A lightweight flatbed semi-trailer body

technical field

The utility model relates to a flat semi-trailer body, in particular to a lightweight flat semi-trailer body. the

Background technique

Existing flatbed semi-trailers are generally made of steel and are composed of base plates, vehicle frames, suspensions and wheel assemblies. Among them, the frame is a frame structure composed of two large I-shaped steel longitudinal beams that are larger than the total length of the bottom plate and several cross beams, providing the load-bearing capacity and rigidity required by the whole vehicle, as shown in Figure 1. Its disadvantage is that the weight of the vehicle frame itself is very large, and the consumption of steel materials will account for 25% of the weight of the vehicle. the

Fiber-reinforced composites are a new type of material that has developed rapidly in recent years. It is usually composed of matrix resin and fiber reinforcement, and there are many methods of preparation, such as vacuum-assisted resin transfer molding (VARTM), etc. Due to the high specific strength and specific stiffness of fiber-reinforced composite materials, it has been widely used in engineering fields and also in the field of lightweight automobile manufacturing. For example, Chinese patent ZL 200510029570.4 discloses a method of using fiber composite materials to manufacture automobile panels. method, although the automobile cover part has the effect of light weight, but the composite material plate can only be used as a cover part and not as a load-bearing structural part, and the inner and outer plates and the core material are glued together, which increases the manufacturing process and has a long production cycle . the

Utility model content

In order to overcome the defects of overweight and serious fuel consumption of the existing flat-bed semi-trailer, the purpose of the utility model is to provide a light-weight flat-bed semi-trailer body. the

The body of the flatbed semi-trailer includes a load-bearing shell, a bottom plate and a support beam, the shell is bonded to the lower surface of the bottom plate and the bottom plate to form a box-like structure, and the support beam is located in the box-packed structure The housing and the base plate are connected internally. the

The support beam is arranged along the length direction of the vehicle body, is located at the center of the box-shaped structure, and its two end faces are attached to the end faces of the housing. the

The vehicle body is made of fiber-reinforced composite material with a thickness of 5-50 mm, preferably 5-20 mm. the

The box-like structure of the vehicle body is in the shape of a cuboid. In order to adapt to the shape of the vehicle front, the end surface of the vehicle body close to the vehicle front can also be changed accordingly, usually an inclined plane. That is to say, the cross-sectional shape along the length direction of the vehicle body can be rectangular or trapezoidal, as shown in FIG. 2 . the

The car body omits the two longitudinal beams of the traditional car body frame, reduces the weight of the car, and relies on the load-bearing shell and the supporting beams in it to bear the load-bearing capacity of the whole car. The depth of the shell and the height of the supporting beam directly determine the ability of the vehicle body to resist deformation under force, that is, the magnitude of the rigidity. the

In the prior art, the weight reduction effect is often judged by analyzing SME (stiffness value per unit mass) (Liu Xiaodong, Lightweight Analysis of Bus Body Structure, Chang'an University, Master's Degree Thesis). The larger the SME value, the lighter the material required to meet the same stiffness, and the better the weight reduction effect. Section properties have an effect on bending stiffness and torsional stiffness. It is obtained from the bending SME calculation formula of rectangular thin-walled rods: in lightweight design, increasing the wall thickness will increase the bending stiffness and mass, but there is no significant change in SME; increasing the section height h, the bending stiffness will increase significantly, and the SME value will increase , the lightweight effect is better; increase the section width, SME has no obvious change, and it will not be considered when reducing weight. From the torsional SME calculation formula of rectangular thin-walled rods, it can be concluded that increasing the height h and width b will significantly increase the torsional SME value, which has nothing to do with the wall thickness. When reducing weight by satisfying the torsional rigidity, it is sufficient to increase the height and width of the section without considering the wall thickness. Considering comprehensively, increasing h can significantly improve the bending stiffness and torsional stiffness of the component. the

In the technical proposal of the utility model, increasing the shell height h can significantly improve its bending stiffness and torsional stiffness. When determining the height of the load-bearing shell of the utility model, the finite element analysis software can be used to analyze the steel car body with the same load capacity to obtain the stress-strain cloud map, and then according to the performance of the lightweight material, according to the steel car body The height h of the load-bearing shell is determined by inversion of the stress-strain contour diagram, which is usually slightly higher than the height of the steel car body beam. For example, the plate thickness of a common 13.6-meter flatbed truck with a load of 40 tons is 2mm, and the height of the large I-beam longitudinal beam is 490mm. The corresponding composite material shell semi-trailer has a shell height slightly higher than 490mm, about 550-600mm about. the

The fiber-reinforced composite material includes a resin matrix and a fiber fabric, and the fiber fabric is high-strength carbon fiber, glass fiber or hybrid fiber, preferably large-tow carbon fiber, and more preferably greater than or equal to 48K large-tow carbon fiber; the resin is not Saturated polyester, vinyl, epoxy, phenolic or acrylate resins. the

Large-tow carbon fiber has low price, easy source, tensile strength generally above 3500Mpa, tensile elastic modulus of 200-230GPa, and performance equivalent to 12K carbon fiber. However, carbon fiber is usually expensive. If production cost control is considered, glass fiber or glass fiber doped with large tow carbon fiber can be used. the

A wear-resistant layer is attached to the upper part of the fiber-reinforced composite material used for the bottom plate, and the wear-resistant layer is one of polydicyclopentadiene, aramid fiber-reinforced composite material, and ultra-high molecular weight polyethylene fiber-reinforced composite material . The thickness of the wear-resistant layer can be determined according to the required wear-resistant and impact-resistant properties, usually 5-10 mm. the

The lower part of the fiber-reinforced composite material used for the bottom plate is provided with a plurality of reinforcing ribs along the transverse and/or longitudinal direction of the vehicle body; preferably, the reinforcing ribs are evenly arranged along the transverse or longitudinal direction of the vehicle body, and the distance between two adjacent reinforcing ribs is 100～1000mm. the

Specifically, the reinforcing ribs may be arranged in a uniform array along the same direction of the bottom plate, or may be a rectangular frame surrounded by one or more layers of reinforcing ribs on the bottom plate, and the outermost rectangular frame and The edges of the bottom plate overlap, and the above two methods can also be combined, for example, a rectangular frame composed of reinforcing ribs is arranged on the edge of the bottom plate, and several reinforcing ribs are evenly arranged in the rectangular frame, etc. the

The reinforcing rib is made of fiber-reinforced composite material through pultrusion or stretch wrapping process; the cross-section of the reinforcing rib is "I", "X", "mouth" or "O". The fiber-reinforced composite material here may be the same as that of the car body, or any fiber-reinforced composite material with high rigidity and good load-bearing capacity in the prior art may be used. the

The fiber form of the fiber-reinforced composite material in the load-bearing shell in the vehicle body and the bottom plate is uniaxial, biaxial, multiaxial, plain weave, twill weave, satin weave or the prepreg of described fabric. the

The fibers in the support beams in the vehicle body are in the form of chopped fibers. the

The cross-sectional shape of the support beam is "I", "X", "W" or "Y". The height of the support beams varies with the height of the shell. the

The outer surface of the car body described in any one of the above technical solutions is also coated with a layer of fiber reinforced composite material with a thickness of 0.5 to 1.0 mm; the fibers are carbon fibers, glass fibers or hybrid fibers, preferably large tow carbon fibers, and more preferably greater than or equal to 48K large tow fiber. the

The outside of the car body is covered with a layer of fiber-reinforced composite material after molding, which can make up for the shortcomings of insufficient bond strength that may be caused by resin bonding alone, and play a role in strengthening the bond at the joints of various components. At the same time, It can also significantly reduce the speed of car body wear. the

The preparation method of the flat semi-trailer car body involved in the utility model is as follows: firstly prepare the load-bearing shell, the bottom plate and the support beam separately; then use resin to bond to form the car body structure; The finished fiber fabric is heat-cured and formed, or the surface of the vehicle body structure is coated with a fiber fabric prepreg, and heat-cured and formed to obtain the vehicle body. the

The car body molding adopts common hand lay-up process, VARTM, RTM or molding process. the

The preparation of the load-bearing shell and the bottom plate adopts vacuum bag molding, VARTM, RTM or molding technology; the preparation of the support beam adopts the pouring molding technology. the

The preparation method of the load-bearing shell is as follows: laying fibers in the mould, and then adding resin, heating and curing to form it. the

The preparation method of the bottom plate is as follows: firstly use the RIM process to form a polydicyclopentadiene resin plate, then put it into a mold, then lay fibers on the resin plate, and finally add resin to heat and cure it. the

The preparation method of the bottom plate also includes laying reinforcing ribs on the fibers. the

The preparation method of the supporting beam is as follows: filling the fiber into the mould, heating and curing the casting resin to form it. the

The above-mentioned forming process can adopt the existing process, and the process conditions such as forming pressure and temperature can be adjusted appropriately according to the difference of the fiber material and the resin matrix. the

The body structure of the light-weight flat semi-trailer described in the utility model adopts a box-shaped integrated structure, which changes the body structure of the existing flat semi-trailer, saves the original frame structure, and makes it have higher resistance. Torsion, bending and load carrying capacity. The body material is made of lighter fiber-reinforced composite material, and its rigidity and load-bearing capacity are equal to or even better than those of steel semi-trailers. Polydicyclopentadiene, aramid fiber composite materials and other wear-resistant and impact-resistant material layers are added to the upper part of the bottom plate. Compared with ordinary fiber-reinforced composite materials for vehicles, they can be used in the load-bearing parts of the car body and expand the fiber-reinforced composite materials. The application of composite materials on the car body enables the entire car body to be lightweight, effectively reducing the weight of the car body. the

The car body described in the utility model can effectively reduce the weight of the car body in terms of structure and materials, generally, it can reduce the weight by 30%-50%, save 8-15% of fuel consumption, and reduce the required traction force by 15-40%. , increasing the cruising range. In addition, because the car body is formed by an integrated method, the manufacturing process is simple, and the connection of each part of the car body is good, which can significantly reduce the number of maintenance and increase the service life. The car body is made of polymer composite materials, which can effectively withstand Corrosion, very good resistance to the action of acids, alkalis, salts, most organic substances and microorganisms. The preparation method of the car body described in the utility model can adopt the existing molding process, the process condition is simple and convenient, and it is suitable for large-scale industrial application. the

Description of drawings

Fig. 1 is the structural representation of flat semi-trailer car body in the prior art;

Fig. 2 is the structural representation of flat semi-trailer car body described in the utility model;

Fig. 3 is the structure perspective view of flat semi-trailer car body described in the utility model;

Fig. 4 is an exploded view of each component of the flatbed semi-trailer car body described in the utility model;

Fig. 5 is a schematic cross-sectional view of the bottom plate of the flatbed semi-trailer car body described in the utility model;

Among the figure: 1, load-bearing shell; 2, base plate; 3, support beam; 21, the composite material laminated plate of base plate; 22, stiffener. the

Detailed ways

The utility model will be further described below in conjunction with the accompanying drawings, and the following examples are also used to illustrate the utility model, but are not used to limit the scope of the utility model. the

With 13.6 meters long, 2.6 meters wide, the flatbed semi-trailer with a load of 40 tons is a model, the lightweight flatbed semitrailer car body described in the utility model is different from the traditional flatbed semitrailer body structure as shown in Figure 1, saving Went for the large I-beam frame. the

As shown in FIG. 3 , the body of a lightweight flatbed semi-trailer includes a load-bearing shell 1 , a bottom plate 2 and a support beam 3 . Wherein, the bottom plate 2 is a flat plate structure, the load-bearing shell 1 is a cuboid structure, and the cross-section along the transverse direction of the vehicle body is an isosceles trapezoid. In order to increase the stability of bonding between the load-bearing shell 1 and the bottom plate 2 , the load-bearing shell 1 is provided with an edge area of about one-tenth to one-fifth of the width of the vehicle body for bonding with the bottom plate 2 . Among the two end faces of the load-bearing shell 1 along the longitudinal direction of the car body, the end face near the front of the car is set in the form of an inclined plane, the angle of inclination is based on the shape of the front of the car, and the end face near the rear of the car is set as a straight face perpendicular to the bottom plate 2. The cross-section of the body 1 along the longitudinal direction of the vehicle body is a right-angled trapezoid. the

When forming the vehicle body, the casing 1 is bonded to the lower surface of the bottom plate 2 and forms a cuboid box-shaped structure with the bottom plate 2, the support beam 3 is arranged inside the box-shaped structure, the upper part is bonded to the bottom plate 2, and the lower part is bonded to the shell The body 1 and the support beam 3 are longitudinal beams, which are arranged along the length direction of the vehicle body. the

Example 1

Taking a flat-bed semi-trailer with a length of 13.6 meters, a width of 2.6 meters, and a load of 40 tons as a model, the weight of an existing steel flat-bed semi-trailer is about 4 tons. the

The fiber material in the fiber-reinforced composite board adopts large tow carbon fiber (≥48K), and the resin is epoxy resin. the

(1) VARTM process is used to form the shell 1. The specific preparation method is: set a metal mold with a heating device, spray HD-918-V release agent (produced by Shanghai Dongheng Chemical Co., Ltd.), respectively, at 0°, + 45°, -45°, 90° Angles of large-tow carbon fiber unidirectional fabric are laid circularly, laying about 8-10mm thick, wrapping the entire mold with a vacuum bag, inserting a sealing strip on the edge of the mold, and vacuuming one end of the mold, 0.05 Hold the pressure at ~0.07MPa for 3-5 minutes, then introduce epoxy resin glue from the other end, and heat and cure. The curing conditions are: temperature, 170°C; time, 2h. After the curing was completed, the temperature was lowered to room temperature, and the casing 1 was obtained after demolding and taking out, and the height of the casing was 600 mm. the

(2) Bottom plate 2, as shown in Figure 5, first uses large tow carbon fiber and epoxy resin to make a 7mm×7mm×1mm (length×width×wall thickness) square tube with a “mouth” cross-section for reinforcement through the pultrusion process Rib 22, and cut into the longitudinal length of the bottom plate of 13.6 meters, then use the RIM process to form a 6mm thick polydicyclopentadiene sheet, and then lay 1mm thick aramid twill fabric and 1mm thick polydicyclopentadiene sheet on the polydicyclopentadiene board respectively The large tow carbon fiber unidirectional fabric forms a laminate 21, and finally lay a layer of reinforcing ribs 22 to 15 mm thick on the uncured laminate 21 along the longitudinal direction of the car body, with an interval of 700 mm between adjacent reinforcing ribs. Using a molding process, the It is placed on a hot press machine for hot-press curing. The curing conditions are: pressure, 0.6 MPa; temperature, 170° C.; time, 2 hours. After curing, cool down to room temperature, take out the mold to obtain the bottom plate 2 . the

(3) The support beam 3 adopts the "I" type, pours epoxy resin into the "I" type variable cross-section combined mold filled with chopped large tow carbon fibers, heats and cures, and the curing conditions are: temperature, 170 ° C; Time, 2h. After curing, cool down to room temperature, open the mold and take out to obtain the support beam 3, the wall thickness of which is about 10mm. the

(4) Bond the formed shell 1, bottom plate 2 and support beam 3 with epoxy resin to form the car body structure, and then wrap 0.5mm thick large tow carbon fiber prepreg cloth around the car body, and then vacuum bag Wrapped, vacuumed, heated and solidified into a box-like overall structure. The curing conditions are: temperature 170°C; time 2.5h. the

The density of epoxy resin reinforced large-tow carbon fiber composite material is 1.6-1.8g/cm ³ , which is about 1/4 of the steel density, and the tensile strength reaches 1600-2100MPa, which is 2-3 times the steel tensile strength (720Mpa). times, but the modulus of elasticity is 110-120GPa, which is about half of the modulus of elasticity of steel (210Gpa). Compared with the same type of steel semi-trailer, under the same load, loading area and rigidity, the car body structure and material selection of Embodiment 1 can reduce the weight by 1.8 tons, save 15% of fuel, and reduce the required traction by 35%. %.

Example 2

Taking a flat-bed semi-trailer with a length of 13.6 meters, a width of 2.6 meters, and a load of 40 tons as a model, the existing steel flat-bed semi-trailer weighs about 4 tons. the

The fiber material in the fiber-reinforced composite board adopts large tow carbon fiber (≥48K) and glass fiber, and the resin is unsaturated polyester. the

(1) The shell 1 is formed by vacuum bag technology, a metal mold with a heating device is installed, and HD-918-V release agent is sprayed, and the angles of 0°, +30°, -30°, and 90° are alternated Circularly lay large tow carbon fiber unidirectional prepreg fabric and glass fiber unidirectional prepreg fabric, laying about 12-15mm thick, wrap the whole mold with a vacuum bag, insert a sealing strip on the edge of the mold, vacuumize, and keep it under 0.05-0.09MPa Press for 3-5 minutes, heat and cure. The curing conditions are: temperature 110°C; time 1.5h. After the curing is completed, the temperature is lowered to room temperature, and the casing 1 is obtained after demolding and taking out, and the height of the casing is 550 mm. the

(2) Bottom plate 2 as shown in Figure 5, first adopts large tow carbon fiber and unsaturated polyester to make cross-section be " I " type, height 10mm leg width 8mm belly thickness 2mm stiffener 22 by pultrusion process, and cut 13600mm and 2584mm long, and then use the RIM process to form a polydicyclopentadiene sheet with a thickness of 6mm, and then lay a 2mm thick multiaxial aramid fabric and a 2mm thick large tow carbon fiber on the polydicyclopentadiene sheet Unidirectional fabric, finally on its uncured laminated board 21, evenly lay a layer of reinforcing ribs 22 to 20mm thick in the longitudinal and transverse directions of the car body, the reinforcing ribs form a rectangular frame, coincide with the edge of the bottom plate, adopt molding process, place it on a heat press for heat press curing. The curing conditions are: pressure, 0.3MPa; temperature, 110°C; time, 1.5h. After curing, cool down to room temperature, take out the mold to obtain the bottom plate 2 . the

(3) The supporting beam 3 adopts the "X" shape, pours the unsaturated polyester into the "X" shape variable cross-section combination mold filled with chopped large tow carbon fiber and chopped glass fiber, heats and solidifies, and the curing condition is : temperature 110°C; time 1.5h. After the curing is completed, it is lowered to room temperature, and the mold is opened to take out the supporting beam 3, and the wall thickness of the supporting beam 3 is about 12mm. the

(4) Bond the formed shell 1, bottom plate 2 and support beam 3 with unsaturated polyester to form a car body structure, and then wrap 0.5mm thick glass fiber twill cloth in unsaturated polyester around the car body The prepreg is then wrapped in a vacuum bag, vacuumed, and heated to cure into a box-like monolithic structure. The curing conditions are: temperature 110°C; time 3h. the

The density of the unsaturated polyester reinforced large-tow carbon fiber and glass fiber hybrid composite material is 1.7-1.9g/cm ³ , which is about 1/4 of the density of steel, and the tensile strength reaches 1400-1800MPa, which is the tensile strength of steel (720Mpa ) 2-2.5 times that of steel, but the modulus of elasticity is 80-100GPa, which is about half of the modulus of elasticity of steel (210Gpa).

Compared with the same type of steel semi-trailer, under the same load, loading area and rigidity, this all-composite material body structure and material selection can reduce weight by 1.6 tons, save fuel by 12%, and require less traction 25%. the

Example 3

Taking a flat-bed semi-trailer with a length of 13.6 meters, a width of 2.6 meters, and a load of 40 tons as a model, the existing steel flat-bed semi-trailer weighs about 4 tons. the

The fiber material in the fiber reinforced composite board is glass fiber, and the resin is vinyl resin. the

(1) The shell 1 is molded by the RTM process, a metal mold with a heating device is set, the HD-918-V release agent is sprayed, and multi-layer glass fiber twill fabric is laid with a thickness of about 15-20mm, and the edge of the female mold is inlaid Sealing strip, seal the female and male molds, vacuumize the cavity (0.05-0.09MPa), hold the pressure under negative pressure for 3-5 minutes, and then introduce vinyl resin glue from the other end, curing conditions is: temperature, 130°C; time, 1h. After the curing is completed, the temperature is lowered to room temperature, the mold is opened and taken out to obtain the shell 1, and the height of the shell is 560 mm. the

(2) The bottom plate is as shown in Figure 5. First, the large tow carbon fiber and vinyl resin are used to make the cross-section "X" shape, 12mm high, 10mm wide, and 3mm thick rib 22 through the conventional pultrusion process, and cut into 2.6 meters. long, and then use the RIM process to form an 8mm thick polydicyclopentadiene sheet, and then lay a 3mm thick aramid twill fabric and a 2mm thick glass fiber twill fabric on the polydicyclopentadiene sheet, and finally place it on the polydicyclopentadiene sheet without A layer of reinforcing ribs 22 to 25 mm thick is evenly laid on the cured laminate 21 along the transverse direction of the vehicle body, and the interval between adjacent reinforcing ribs is 500 mm. The reinforcing ribs are arranged along the width direction of the vehicle. Cured by heat and pressure. The curing conditions are: pressure, 0.4MPa; temperature, 130°C; time, 1h. After curing, cool down to room temperature, take out the mold to obtain the bottom plate 2 . the

(3) The supporting beam 3 adopts a "W" shape, pours vinyl resin into a "W" shape variable cross-section combined mold filled with chopped glass fibers, heats and cures, and the curing conditions are: temperature, 130°C; time, 1h. After curing, cool down to room temperature, open the mold and take out to obtain the support beam 3, the wall thickness of the support beam 3 is about 15mm. the

(4) Bond the formed shell 1, bottom plate 2 and support beam 3 with vinyl resin to form the car body structure, then wrap 1.0mm thick glass fiber twill prepreg cloth around the car body, and then vacuum bag Wrapped, vacuumed, heated and solidified into a box-like overall structure. The curing conditions are: temperature, 130°C; time, 2h. the

The density of vinyl resin reinforced glass fiber composite material is 1.8-2.0g/cm ³ , which is about 1/4 of the density of steel, and the tensile strength reaches 1200-1600MPa, which is 1.6-2.3 times of the steel tensile strength (720Mpa). However, the modulus of elasticity is 50-80GPa, which is about 1/3 of the modulus of elasticity of steel (210Gpa).

Compared with the same type of steel semi-trailer, under the same load, loading area and rigidity, this all-composite material body structure and material selection can reduce weight by 1.3 tons, save fuel by 9%, and require less traction 18%. the

Although the utility model has been described in detail with general description, specific implementation and experiments above, some modifications or improvements can be made on the basis of the utility model, which will be obvious to those skilled in the art of. Therefore, the modifications or improvements made on the basis of not departing from the spirit of the utility model all belong to the protection scope of the utility model. the

Claims (10)

1. lightweight flat bed trailer car body; It is characterized in that; Comprise load-bearing housing (1), base plate (2) and support beam (3); Lower surface and said base plate (2) that said housing (1) is bonded in said base plate (2) form box like structure, and said support beam (3) is positioned at said box like structure and connects said housing (1) and base plate (2).

2. flat bed trailer car body according to claim 1 is characterized in that, said support beam (3) is provided with along said length over ends of body direction, is positioned at the center of said box like structure, and the end face of its both ends of the surface and said housing (1) fits.

3. flat bed trailer car body according to claim 2 is characterized in that, said car body adopts fiber reinforced composite, and its thickness is 5～50mm; Said fiber reinforced composite are by the moulding that is heating and curing of resin matrix and fabric; Said fabric is carbon fiber, fibrous glass or assorted fibre; Said resin is unsaturated polyester (UP), vinylite, epoxy resin, phenol resin or acrylate resin.

4. flat bed trailer car body according to claim 3 is characterized in that, the thickness of said car body is 5～20mm.

5. flat bed trailer car body according to claim 3 is characterized in that, said carbon fiber is the large-tow carbon fiber more than or equal to 48K.

6. flat bed trailer car body according to claim 3; It is characterized in that; The fiber-reinforced composite material board top that is used for said base plate (2) is stained with wearing layer, and said wearing layer is a kind of in polydicyclopentadiene, aramid fiber reinforced composite, the superhigh molecular weight polyethylene fibers reinforced composite.

7. flat bed trailer car body according to claim 3 is characterized in that, the fiber-reinforced composite material board bottom that is used for said base plate (2) is provided with many reinforced ribs along cross-car and/or longitudinal direction; The spacing of adjacent two reinforced ribs is 100～1000mm; Said reinforced rib be fiber reinforced composite through pultrusion or draw and twine technological forming and make, its cross section is " worker " type, " X " type, " mouth " type or " O " type.

8. flat bed trailer car body according to claim 7 is characterized in that said reinforced rib evenly is provided with along cross-car or longitudinal direction.

9. flat bed trailer car body according to claim 3 is characterized in that, the shape of cross section of said support beam is " I " type, " X " type, " W " type or " Y " type.

10. according to each described flat bed trailer car body of claim 1-9, it is characterized in that said car body outside face is coated with the thick fiber reinforced composite of one deck 0.5～1.0mm.

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